The study of archaeological site formation processes, although routinely undertaken for prehistoric sites, is only carried out in historical archaeology in a limited way. Understanding the processes which formed the archaeological record of a site is an important first step towards developing justifiable inferences about past behavior and past societies regardless of the age of the site. This paper identifies and examines the cultural and non-cultural processes that formed the archaeological record at the Commissariat Store, Brisbane. The history of the site, from its construction in 1829 as part of the Moreton Bay penal settlement to the present, is examined and the expected impacts and processes on the archaeological record are identified. Archaeological evidence from the salvage excavation of the site undertaken in 1978 and 1979 is analyzed to identify the cultural and non-cultural site formation processes. This study identifies the presence of cultural formation processes including discard, loss, abandonment and re-use from an examination of the historical and archaeological evidence. Non-cultural formation processes at work in the site include faunalturbation, floralturbation, flooding, and aquaturbation.