A survey of all anaesthetists in the West Midlands region--that is, 10% of all the anaesthetists in England and Wales--showed that one in 10 of their children had been referred to a consultant because of a congenital or nonacquired anomaly. Abortions among anaesthetists' families were also common but more so when the mother was an anaesthetist. The anomalies were concentrated particularly in the central nervous system and musculoskeletal system, and girls were worst affected. The mean birth weights were below normal, more so when the mothers were anaesthetists. Girls with anomalies were particularly underweight. Other effects observed were unexpected infertility, cancer both in the adults and in the children, and, possibly, impaired intellectual development in the children. Many anaesthetising areas were inadequately ventilated, and scavenging devices despite their inefficiency are recommended as a stopgap measure. The results of the study closely resemble those of other studies with similar high response rates to requests for information.