This historic place was registered under the Historic Places Act 1980. The following text is the original citation considered by the NZHPT Board at the time of registration. The Post Office at Port Chalmers was built in 1877 by the Public Works Department and possibly designed by P.F.M. Burrows. It is L shaped in plan with a single storey block being contained within the L. The building is in a simplified Renaissance style and is made of locally quarried Port Chalmers stone. The corners of the building have rusticated quoins, and double-hung sash windows are contained within simplified segmented arched frames. There is a double entrance, with the left hand door opening onto the living accommodation. Still in use as a Post Office, the building is located on the edge of the dock area of the port at the end of the main street giving it considerable townscape qualities. It is a significant example of an early small town Post Office constructed in stone.