We reviewed all cases of malignant melanoma in children younger than 17 years of age who were evaluated at Sainte Justine Hospital, a tertiary care pediatric center, between 1980 and 2002. The medical records and histologic features of all cases were reviewed. Thirteen cases were identified, 4 boys and 9 girls. Fifty-three percent of patients were prepubescent. None of the patients had a predisposing condition (eg, giant congenital nevi, dysplastic nevus syndrome, or xeroderma pigmentosum). One patient had had chemoradiotherapy previously for an undifferentiated pleuropulmonary malignant tumor (blastoma) and another patient had Down syndrome. The most frequent reason for initial consultation was a recent increase in size of the lesion. Three patients had pyogenic granuloma–like lesions. Eighty-five percent of the observed melanomas were nodular in type. Tumor thickness ranged from 0 to 6 mm with a median and mean thickness of 2.8 and 3.2 mm, respectively. The overall 5-year survival rate was 58.8%. Lack of awareness and delay in diagnosis may lead to a higher incidence of thick and intermediate melanoma in children. Because it appears that the majority of melanomas in childhood and adolescence occur de novo, clinicians should consider this condition in the differential diagnosis of any suspect lesion in children and adolescents even without an identified predisposing factor.