Lymphangiomas are relatively rare congenital hamartomas of the lymphatic system usually diagnosed in infancy and early childhood. Although the precise pathogenesis has not been clearly defined, abnormal development leads to formation of fluid-filled sinuses lined by vascular endothelium. In the head and neck, lymphangioma may encroach on vital structures and infiltrate surrounding tissues making complete surgical removal difficult. A number of children (n = 137) with lymphangioma have been treated at Texas Children's Hospital from 1972-1985. In 45 (33%), the tumors were diagnosed at birth and in an additional 51 (37%), by two years of age. Commonly affected areas included the head and neck (45%), trunk (26%), and axilla (17%). Mediastinal involvement occurred in 4%. Surgical removal was the preferred treatment method and with complete removal the recurrence rate was 6%; known incomplete removal increased this rate to 35%. Although lymphangiomas are slow growing, early removal was preferable: recurrences increased as the time interval between tumor identification and surgical intervention lengthened. Size fluctuation with a history of infection, another unfavorable prognostic factor, also increased recurrence rate.