The National Board of Navigation in Finland employed 942 sea pilots in 1956-85, during which time 262 of them died (SMR = 77, 95% CI = 68-86). The male population in southwest Finland served as control. The causes of deaths were collected from death certificates. The mortality rate for all cardiovascular diseases and lung cancer was lower among sea pilots than in the comparison population (SMR = 83, 95% = CI 69-97 and SMR = 67, 95% CI = 37-97) while for ischaemic heart diseases, it was similar to that of the population as a whole (SMR = 96, 95% CI = 77-115). Health selection due to ischaemic heart disease was seen in the lower mortality rates among young pilots who started work in 1956-85. Otherwise, the slightly higher rates may indicate a possibility of adverse health effects of sea piloting.