We studied 25 children, age 7 months to 12 years 6 months, with anogenital warts, and their parents. In most children the warts were localized in the anal area, in 3 of 18 girls perianally and on the vulva, and in 4 girls exclusively on the vulva. Southern blot hybridization studies disclosed an association of condylomata with human papillomaviruses (HPV) 6 and 11 in 74% and HPV 2 in 17.4% of patients. The clinical features were similar in warts induced by genital and cutaneous HPVs. Even the HPV 2-associated warts in the vulva of two girls were typical of condyloma acuminatum. In all children with HPV 2-induced condylomata, cutaneous common warts coexisted, also induced by HPV 2. However, three mothers had cutaneous warts, and the children's condylomata were associated with HPV 6. Thus, the mere presence of skin warts in family members does not rule out other sources of infection. Sexual abuse was suspected in four girls and two boys, but was not confirmed in any. Nonsexual transmission could occur by persons with the lesions taking care of children. Perinatal transmission also appears to be an important route of infection in small babies. Infection in utero was probable in one girl in whom anal warts appeared in the first week of life and whose mother had cervical condylomata during pregnancy. This study provides further confirmation of possible nonsexual transmission of genital HPVs and the not infrequent association of childhood condylomata with HPV 2.