Skeletal ages of patients with streak gonad syndrome were determined by the Schinz and TW2 methods as well as by bone scans. Seventy-three subjects were examined. They were classified according to their chromosomal complement, body height, chronological age and previous hormonal treatment. Retarded bone age was a common finding on the hand, wrist, hip, knees and spine with significant coexistence; however, the extent of delay in skeletal maturation on various bones differed considerably. There was no significant correlation between bone age and chronological age, karyotype, body height and previous hormonal replacements, respectively. This finding suggests that retarded skeletal maturity in streak gonad syndrome is neither the consequence of estrogen deficiency nor due to sex chromosome abnormalities and probably is not dependent on growth hormone secretion. Its pathogenesis appears to be multifactorial and remains to be determined.