Two hundred and ninety-seven patients with 375 pediatric vascular lesions were followed from 1967 to 1981. By history and physical examination, 96% of childhood vascular lesions can be classified as hemangiomas or malformations. Hemangiomas are often not present at birth (40%), but make their appearance during the first month. A proliferative phase, lasting an average of 3 months, is followed by a slow, but eventually complete involution. A "perfect" cosmetic result is more likely when involution is complete before age 6. Malformations are always present at birth, their growth is commensurate with the patient's, and they never involute. Analysis of clinical characteristics fails to identify a subgroup of hemangiomas destined for early involution.