This paper describes the results of a search for the obstetric records of a cohort of over 5,000 children who participated in surveys of childhood diet and growth during the late 1930s and early 1940s conducted by the Rowett Research Institute in Aberdeen. The surveys were conducted at sixteen centres throughout England and Scotland. Birth-weight data were found in hospitals, health authority archives and local authority record offices for approximately 10 per cent of these children. The sources and methods used to find the records are described and their representativeness is evaluated. It is anticipated that this report will be of some interest to medical historians and epidemiologists conducting retrospective studies.