The relationship of temperament to pre- and posthospital behavioral responses of school-age children was examined in this study. Seventy-five children, aged 8 to 12, who experienced unplanned hospitalizations were studied. Data were collected from the children's mothers who served as the primary informants. The mothers completed questionnaires describing their children's temperament and behavior pre- and posthospitalization. Temperament accounted for more than 50% of the variance in the children's behavior prior to hospitalization and at 1 week and at 1 month following discharge. The subjects usual prehospitalized temperament was significantly more withdrawn than the established norms of the temperament instrument. However, the subjects did not differ from the norms at either 1 week or 1 month following discharge.