Kempsey Post Office is associated with the early development of the town, as it is linked with the original postal services established in 1843 in East Kempsey, and in 1859 in West Kempsey. Kempsey Post Office has been the centre of communications for Kempsey for over a century, and reflects the growing population and increasing demands for mail, telegraph and telephone services in the area.

Kempsey Post Office also provides evidence of the changing nature of postal and telecommunications practices in NSW. The brief period when Kempsey Post Office became a Distributing Post Office to the local area in the early 1980s is also of some historical significance.

Kempsey Post Office is aesthetically significant because it is a particularly fine and distinguished example of the Victorian Italianate style, and makes an important aesthetic contribution to the civic precinct in Kempsey. Kempsey Post Office is also associated with the Colonial ArchitectFs Office under James Barnet, a key practitioner of the Victorian Italianate style of architecture.

Kempsey Post Office is also considered to be significant to the Kempsey communityFs sense of place."

The building has a hipped roof of green corrugated steel and the clock tower is capped by a pyramidal corrugated steel roof. The clock tower has four clock faces installed of unusual design, having white lettering and hands on a black face. The two storey section has three rendered and cream painted corbelled brick chimneys with terracotta pots, punctuating the eastern and northern sides of the building and at the centre.

The ground floor of the western facade is classically detailed, with a three-bay arched masonry colonnade, with tan painted keystones to the centre and tan and red painted dentilled entablature above. The colonnade is paved with red clay tiles and has a plaster soffit with moulded cornice. The first floor is face red brick with rendered quoining to corners, a wide rendered band below window sill level and bracketed eaves. This band extends to form a balustraded parapet wall to the single-storey northern addition. The square corner tower has classically detailed arched windows to the first floor level and red painted rendered background to the clock faces of the second level, surmounted by a squat belvedere. There is a recent, intrusive concrete ramp and stairs to the front colonnade.

The southern facade is red face brick with cream painted, rendered string courses at ground floor window sill level and ground floor eaves level. There is a recent, intrusive concrete ramp at the centre of the facade matching the ramp to the western facade, accessing the post boxes located within a recessed, tiled porch.

Kempsey Post Office appears to have been constructed in four main stages. These include the original two-storey section with corner tower, followed by the single-storey infill to the north in c1904, the eastern single-storey complementary face brick wing addition of c1927{28 and the later, detached, single-storey weatherboard addition along the northern boundary.

The main building has been altered and added to substantially since first constructed, a major change being the addition of the complementary stretcher bond brown brick, single-storey wing to the eastern facade of the original two-storey building along the southern boundary.

Flush against the adjacent building is a long, single-storey addition of weatherboard and asbestos cement sheet, with a corrugated steel skillion roof. This addition comprises staff amenities to the western end and cycle shed and storage to the eastern end. There is a carport at the easternmost end of this addition.

Fenestration of the building is regular. There are arched and squared sash windows to the ground floor, with a fixed multi-pane window over the post boxes to the southern facade. There are tan painted, flat arched lintels over the southern facade windows and rendered voussoirs to the western facade. Doors to the building are non-original; however, there are some earlier doors with decorative fanlights located to the western porch side walls. There are recent automatic sliding glass doors located behind the centre arch to the colonnade.

The ground floor of Kempsey Post Office comprises four main areas, including the carpeted retail area at the western end of the building with the standard Australia Post fitout of display wall panels and laminated counters in a grey colour scheme. The three remaining areas include large sheet vinyl areas for mail sorting, storage and contractors to the rear of the building, offices at the centre and staff amenities within the later weatherboard addition to the north.

The ceilings of the ground floor include plaster, board and batten, and plasterboard, all with moulded cornices. There are several exposed beams and the lighting of the ground floor consists of suspended fluorescent lights. Intrusive air conditioning ducting is suspended from the ceiling.

Architraves to the ground floor openings appear to be original or early. There are sections of original skirting left to original wall fabric showing the effects of general wear and tear and there is a cut dado line in the wall render. Walls are predominantly rendered brick in a pastel pink colour scheme, with plasterboard stud walls enclosing the retail area and office behind. No fireplaces appear to have been retained to the ground floor.

Two original four-panel doors are retained to the current cleanerFs room and adjacent store; however, the remaining internal doors are modern and there are fanlights over external doors.

The main stair is not original and has been constructed within the base of the clock tower. It is a complex polished timber stair with squared posts and balusters, having a yellow/beige sheet vinyl floor with black edge strips.

The first floor of the Post Office and former residence currently contains the carpeted Postal ManagerFs office in the southeastern corner, sheet vinyl storage rooms to the northeastern corner and at the eastern end of the stair hall, and a large, carpeted lunchroom to the west. Later toilets with mosaic tiling are also retained to the north at centre. The first floor currently has an overall pastel green colour scheme.

The ceilings to the first floor comprise board and batten to the lunch room, plasterboard with a coved cornice to the hallways, plaster with a wide, simply moulded cornice to the office and storage room and asbestos cement sheet with a quad-mould cornice strip to the toilet areas. Lighting is suspended fluorescent, except in the toilets where attached globes are used. Air conditioning vents are located in the ceilings and there are some units on the walls. Architraves to the first floor openings appear to be original and have been painted. Skirtings also appear to be original and intact.

There are predominantly single upper and lower pane sash windows to this level with red-brown painted frames and there is one multiple upper, single lower pane window to the eastern wall of the Postal ManagerFs office. There is a large fixed multi-pane internal window above the partition wall to the western side of the Postal ManagerFs office. One original four panel internal door is retained to the first floor of the northern wall of the Postal ManagerFs office, the remainder being modern flush and half glazed doors.

Walls of the first floor are largely rendered and painted original brick fabric with moulded corners. Asbestos or fibre cement sheet partition walls are located to the eastern and southern side of the lunch room, the western wall of the Postal ManagerFs office and the toilet additions to the north. Picture rails are located on the original wall fabric of the Postal ManagerFs Office and the adjacent hallway to the west. Fireplaces to the first floor have been bricked in, and surrounds retained to the lunch room, Postal ManagerFs office and adjacent store to the north.

Signage to Kempsey Post Office comprises dark lettering across the western facade below the first floor window sills on the wide, cream painted rendered band and a standard Australia Post sign on a post located at the corner of the building.

The Post Office is located on a prominent corner at an important intersection in Kempsey. It is adjacent to the Macleay River bridge and is important for its architectural quality and townscape value. It is a dominant feature in the streetscape and is surrounded by twentieth-century, two-storey shopfronts

There is landscaping to both facades of the building, including low, dense vegetation to the front footpath and some large trees, grass and planters to the side. Seating to this side is also provided, as is a low timber rail fence, bins and a twin telephone booth. Display lighting to the clock tower is located on posts to the front and side of the tower and the footpath is made up of concrete pavers.

Kempsey Post Office is generally in good condition; however, some cracking, peeling paint, previous patching and general wear and tear is evident to the interior walls, particularly the ground floor.

There is some archaeological potential for the site considering the numerous additions and alterations that have occurred over time and the openness to the rear of the site. There is potential for recovering evidence of earlier buildings or structures, such as the previous building on the site used as a hotel."