Childhood injuries are a major source of morbidity and mortality in industrialized countries, and many injuries occur on playgrounds. Our purpose was to examine childhood playground injuries in a metropolitan center in Canada. All children injured on playground equipment who were seen in the emergency department (ED) at The Hospital for Sick Children between March 1990 and July 1991 and were entered in the Children's Hospital Injury Research and Prevention Project (CHIRPP) database were included. The type, body part, and mechanism of injury were determined as well as the type of equipment, location, and surface. Among the 289 children injured on playground equipment, the mean age was 5.9 years with 39% < 5 years (range: 1 to 18 years). The most common injuries included fractures (28%), lacerations (24%), and hematomas (14%). The head and neck were injured 43% of the time, the upper extremity 41%, lower extremity 10%, and the trunk 6%. Climbing apparatus injuries occurred in 29% of children < 5 years compared with 47% of those injured who were > or = 5 years (P = 0.002). Injuries related to slides occurred in 40% of children < 5 years compared to 26% of children > or = 5 years (P = 0.033). Of children < 5 years, 58% had head and neck injuries compared to 32% of children > or = 5 years (P = 0.0006). Of children < 5 years, 28% had upper extremity injuries compared to 49% of children > or = 5 years (P = 0.0005). There were no fatalities and the overall hospitalization rate was 18%. Of those children hospitalized, 77% had fractures, compared to 16% of those not hospitalized (P = 0.00001). Of all children hospitalized, 62% were injured on climbing apparatus, compared to 37% of those not hospitalized (P = 0.0004). There were no significant differences between nonprotective and natural protective surfaces with respect to hospitalization. We conclude that: 1) upper extremity injuries, especially fractures, accounted for the majority of hospitalizations resulting from injuries on playground equipment; 2) climbing apparatus-related injuries accounted for nearly two thirds of hospitalizations; 3) older children sustained more injuries on climbing apparatus, where younger children sustained more injuries on slides; and 4) younger children sustained more head injuries on playground equipment than older children, but most of these were minor.