Twin pregnancy is an important risk factor associated with cerebral palsy (CP). We investigated the prevalence and clinical features of CP in twins born from 1988 to 1994 in Okinawa prefecture. The prevalence of CP in twins was 10.1 per 1000 multiple births, and it was 6 times that in singletons (1.6 per 1000 live births). Twins weighing more than 2500 g had a higher prevalence of CP than singletons, but those weighing less than 2500 g had no significant difference. Our results indicate that the higher rate of CP in twins reflect their tendency to be low-birth weight. There may be specific events affecting twins weighing 2500 g or more.