The total prevalence rate of tracheo-oesophageal fistula and oesophageal atresia in 15 EUROCAT registries covering 1,546,889 births during 1980-8 was 2.86 per 10,000. There was a decreasing prevalence rate over time (3.5 per 10,000 in 1980-2, 2.7 in 1983-5, 2.5 in 1986-8). Ten per cent of cases were associated with chromosomal anomalies and of the remaining cases, half were multiply malformed. Sixty two per cent of cases were males. There was a significantly increased risk for mothers of less than 20 years of age (odds ratio compared with mothers of 25-29 = 1.82, 95% confidence interval 1.23 to 2.67). There were no apparent epidemiological differences between isolated and multiply malformed cases in secular trend, sex ratio, or maternal age. Both isolated and multiply malformed cases tended to be premature and small for gestational age. There was variation between centres in survival of affected liveborn children up to 1 year of age.