Long-term mortality from congenital cardiovascular malformations (CCVM) remains unknown in most countries. Age- and sex-specific mortality rates from CCVM in Japan from 1968 through 1997 were determined from analyses, with official permission, of individual death records held by the Japanese Government. CCVM with chromosomal anomalies were not included. The number of deaths analyzed was 82,919. The mortality rate declined by 64% from 3.36 per 100,000 population in 1968 to 1.22 in 1997, largely because of a decrease in mortality among patients under 20 years of age. Infant mortality remained high until 1978, then sharply declined from 1979 to 1987 with the advent of 2-dimensional echocardiographic diagnosis and prostaglandin El therapy. The cumulative mortality rates in the first 20 years of life were expected to decline among cohort members born after 1978. In contrast, the mortality rates for subjects over 20 years of age increased during the 30-year study period. Mortality rates were higher for males than for females. The mortality rate among young patients with CCVM is expected to decline still further, suggesting that many if not most children with CCVM will survive to adulthood.