After the Chernobyl accident serious concern spread throughout Italy about the possible effects of the consequent exposure to radioactivity on fetuses. A reduction of births in the first three months of 1987, and particularly in February (7.2% reduction in the birth rate), was observed throughout Italy. In April-June 1987 a 4.8% increase in the number of births was observed. The magnitude of both phenomena varied in different areas of the country. The total number of births in the first six months of 1987 was very similar to the expected (264,241 versus 263,659). Induced abortions increased in Lombardia (northern Italy) in June (+1.6%) and July of 1986 (+3.4%) and in Campania (southern Italy) in June (+12.7%) and August (+4.3%). No increase in legal abortions was detected in Lazio (central Italy). Italian data suggest a voluntary decrease in the number of planned pregnancies and the termination of some of them in the first weeks after the accident as a consequence of postdisaster stress.