Introduction: Media focus on health problems among personnel in the Royal Norwegian Navy spurred a broad scale investigation, including cancer incidence and mortality studies. The studies were planned as historical prospective cohort studies.
Methods: Cohorts of military and civilian personnel serving in the Navy during 1950 to 2005 were established by manually entering paper-based service history files into the data system at the Headquarters Defence Command Norway. The files were collected from Headquarters Defence Command Norway, the naval bases, and the National Archives of Norway.
Results: The military cohort consists of 29,056 officers and enlisted personnel (2.5% women) with an average of 6 years of service in the Navy. Year of birth spans 1883 to 1985; the median is 1954. The cohort of 8,378 civilians (39% women) has an average of 11 years in the Navy; the year of birth spans 1884 to 1988 with a median of 1942. Both cohorts are regarded as virtually complete.