We report four cases of true hermaphroditism. The first patient (legal sex female, karyotype of 46, XX/46, XY, bilateral ovotestis) was changed to a male at 2 years old. The second patient (karyotype of 46,XX/47, XXY/48, XXYY, hypospadia, and right undescended testis) was referred to us at 6 months old, and turned out to have a uterus, an ovary on the left side and a testis on the right side. The third patient (6 months old, karyotype of 46, XX/46, XY, hypospadia) had an ovotestis on the right side and a testis on the left side. The fourth patient (1 year and 6 months old, a karyotype of 46,XX, hypospadia) had bilateral ovotestis. All four patients showed a variety of responses of testosterone to human chorionic gonadotropin stimulation. They were grown as males. It is difficult to treat a case of true hermaphroditism including determination of sex. We should consider the results of chromosomal analysis, hormone values, imaging studies and histology of gonads, and determine appropriate sex.