In a review of 102 cases with various intersex states, the frequency of intratubular germ cell neoplasia (IGCN) unclassified in testes of children and adolescents was 6%. It was seen in 2 of 87 cases in the prepubertal age group and 4 of 23 cases in the pubertal age group. The frequency of IGCN was 0 of 23 in androgen insensitivity syndrome (testicular feminization), 3 of 38 in gonadal dysgenesis, 1 of 12 in true hermaphroditism, 1 of 22 in male pseudohermaphroditism, and 1 of 7 in the group with multiple congenital anomalies and ambiguous genitalia. Five cases showed unilateral and one showed bilateral IGCN. Three pubertal cases had unilateral gonadoblastoma associated with IGCN. Invasive germ cell tumor was absent in all six cases. The atypical germ cells in all testes with IGCN showed immunoreactivity with placental alkaline phosphatase. Review of the literature revealed 30 prepubertal and pubertal cases with IGCN. The median age of the combined series of 36 cases with IGCN was 13 years (range 1 month to 19 years). Concomitant invasive tumor was present in 3 of 14 cases with gonadal dysgenesis and IGCN and 2 of 18 cases with androgen insensitivity and IGCN.