Children with 17beta-hydroxysteroid-dehydrogenase-3 (17beta-HSD-3) deficiency have a defect of testosterone biosynthesis with subsequent diminished virilization in XY individuals. Some are raised as girls and some as boys. There were two purposes of this case report: First, it analyzed the process of decision-making in a family with a pair of siblings with identical mutations leading to 17beta-HSD-3 deficiency whose parents chose to raise one child as a boy and one as a girl. This analysis was based on narrative interviews with the parents. Second, we assessed the gender role behavior and gender identity in the children to examine if the psychosexual development of these children correspond with the sex of rearing their parents chose. When participating in the study, the children were 7 (boy) and 5 (girl) years old. Parents described a difficult process of decision-making and voiced concerns about lack of appropriate and understandable information, and anticipated decision regret. However, they did not feel that the decision to "normalize" the external genitalia should have been deferred. Both children appeared to show age-typical gender-related behavior and did not show any signs of physical or mental distress.