The prevalence of cerebral palsy (CP) in Swedish infants born in the four-year period 1979-82 is reported and related to the prevalence in infants born during the twenty-year period 1959-78. In 1979-82 it was 2.17 per 1,000 livebirths, 1.23 for children born at term and 0.94 for preterms, which means that the rising trend since the beginning of the 1970s persisted. The most pronounced rise, from 0.18 per 1,000 livebirths in the period 1967-70 to 0.67 in 1979-82 was found in the subgroup of preterms with spastic/ataxic diplegia. The severity of motor disability and the relative frequency of mental retardation, infantile hydrocephalus and epilepsy among preterm CP children successively increased over the same period of time. The livebirth prevalence of CP in term infants increased slightly but non-significantly during the period 1967-82. The birthweight-specific prevalence of CP per 1,000 newborns surviving the first week of life increased in all birthweight groups during the period 1967-82, significantly for birthweights below 1,500 g and over 2,500 g. The rising prevalence of CP was concomitant with a parallel fall in perinatal mortality, especially in very preterm infants. In the 1980s, severely multi-handicapped, very preterm children, only exceptionally seen among CP children born in the 1960s and 1970s, has become a matter of concern.