Report on a programme of archaeological investigative works, conducted in advance of residential development on land at 45-47 St Catherines, Lincoln. Originally planned as two trial trenches, the investigation was widened to full excavation of the proposed new building footprint after significant medieval features were identified. These features comprised a large number of human cist burials and the remains of several structures, clearly associated with the Gilbertine Priory of St Catherine's, and representing multiple phases of cemetery use and construction activity. Remains of late 19th residential development were also recorded on the site, and three redeposited flints of probable Neolithic date were recovered.