The Study of Men Born in 1913 is a prospective population study of cardiovascular diseases in Gothenburg, Sweden, that started in 1963. To describe survival curves and mortality pattern, all boy-children born alive in 1913 in the city of Gothenburg, were identified. This birth cohort was followed from birth to age 70 for residence, vital status and cause of death. At the age of 50 years, 25% of the birth cohort were dead and at age 70, 43% had died. The high infant mortality and the great impact of infectious diseases in the beginning of this century is illustrated. The death rate for the cohort was almost identical to national figures for men in the same age group. Men who migrated from Gothenburg had a death rate very similar to those who stayed. It can therefore be concluded that the men in the Study of Men Born in 1913 is a representative sample not only of men in Gothenburg but also of men in Sweden as far as mortality is concerned. Special attention was paid to death from otitis media complications, congestive heart failure, and diabetes. Few persons died from these diseases before age 50 when the prospective study started and therefore did not influence the study of the natural history for these conditions to any great extent. Otitis media infections might be studied retrospectively from this age.