Steroid 5-alpha-reductase 2 deficiency is a rare disorder leading to male 
pseudohermaphroditism, a condition characterized by incomplete differentiation 
of male genitalia in 46,XY patients. Here, we report a case of a 21-year-old 
woman from Ardabil who presented with primary amenorrhea, ambiguous genitalia, 
and lack of breast development. All of the serum hormone profiles were normal 
except for raised serum total testosterone. Testosterone to DHT ratio (T/DHT) 
was elevated before (15.72) and further increased after hCG stimulation (32.46). 
A chromosomal study revealed a 46,XY karyotype. A bilateral gonadectomy, 
recessive cliteroplasty, urethroplasty, and vaginoplasty were performed and 
hormonal replacement therapy using estrogen was started. In conclusion, the 
diagnosis of 5-alpha-reductase 2 deficiency may be suspected in infants with 
ambiguous genitalia or in adolescents or young adults with the characteristic 
phenotype and serum hormone profiles.