Dysgenetic male pseudohermaphroditism is the result of a defect of testis development that encompasses a large clinical heterogeneity. It is characterized by bilateral dysgenetic testis, absence of mullerian regression, ambiguous genitalia and/or stigmata of Turner's syndrome in the majority of the cases. Typically, these individuals have either a 46,XY or 45,X/46,XY karyotype. The authors present four cases of dysgenetic male psudohermaphroditism, with ages of diagnosis between 1 month and 17 years old. The first had a male phenotype with stigmata of Turner's syndrome and the others ambiguous genitalia. Two patients were 45,X/46,XY and 45X/47,XYY mosaics and the other two were 46,XY. Gonadal karyotyping showed mosaicism (45,X/46,XY) in all four cases. In the first case was programed orquidectomy; all the others assigned a male gender, with regular follow-up until the puberty.