This study examines the prevalence of cerebral palsy (CP) in two north-east Italian provinces, Padua and Rovigo (overall population 1030 000). Six-hundred and ten children with a diagnosis of CP (330 male, 280 female), born between 1965 and 1989, were studied. The prevalence of CP progressively increased from the 1960s to the mid-1980s, and then decreased in the 5-year period, 1985 to 1989. These quantitative changes were associated with qualitative ones. For example, the number of low-birthweight (LBW) infants progressively increased, similar to results of epidemiological studies from other European countries. The clinical features of the types of CP in this study (hemiplegia, diplegia, ataxic diplegia, quadriplegia, pure ataxia, dyskinesia) generally correspond with those described in other studies. However, the prevalence of quadriplegia in this study is higher. The prevalence of types of CP related to preterm birth, such as diplegia, increased over the years, while those associated with term babies, such as dyskinesia, decreased. This study suggests that prenatal factors are associated with some types of CP, while in others, such as diplegia, quadriplegia, and dyskinesia, the perinatal factors are notable. Perinatal factors were associated with LBW children, while prenatal factors were greater for normal-birthweight infants. The variation in the prevalence of CP over the years, with two peaks corresponding with the introduction of neonatal intensive care units in Padua and Rovigo, suggests that changes in neonatal care could influence the levels of CP, independent of the original presence of predisposing prenatal factors.