Colley-Priest continued carrying wounded throughout the war. In 1917, he was awarded the Military Medal for bravery in the field while rescuing wounded at Bellewaarde Ridge in the Ypres sector under heavy fire.

After the war, Colley-Priest published an abridged version of his diary under the title ‘The 8th Australian Field Ambulance on active service: a brief account of its history and services from 4 Aug. 1915–5 Mar. 1919‘, Sydney, DS Ford, 1919.

In the early 1920s, Colley-Priest was instrumental in organising reunions of members of the 8th Field Ambulance. They met at the café Sargent’s in Sydney.

In 1925, Colley-Priest was presented with a rolltop desk in recognition of his work in organising the 8th Field Ambulance reunions.

Colley-Priest drowned at Balmoral Beach in Sydney in February 1928. At the time, the press speculated that he had suffered from depression and committed suicide.