A retrospective study supplemented with follow-up was carried out in 163 children, aged 6 months to 16 years, who were hospitalized because of acute, recurrent or chronic urticaria in 1976–1980. Etiologic agents were identified in 55% of cases. Physical factors were the commonest causes, especially in cases of chronic urticaria, while infections predominated in acute urticaria. 81% of the children participated in the follow-up study. Follow-up for a year or more revealed that 53% of the children had become symptom-free, 36% still had symptoms but less frequently and in 11% urticaria are similar to those found in adults and that prognosis is favorable, particularly when the etiology is established.