An Italian nationwide presentation of data concerning the proportion of births by caesarean section (CS) for the period 1980-1985 is presented here. A constant increase in CS was noted, from 11.2% in 1980 to 15.8% in 1985. The increase was observed in all regions while higher rates were noted in northern and central Italy. CS rates are higher in older age groups, in pregnancies from 29th to 35th week of gestation for high and low birthweights and malpresentations. Ecological associations revealed that CS is positively related to economic development and negatively to perinatal and stillbirth rates.