Obstructive uropathy, secondary to mass obstructing effects such as hematometrocolpos and consequent acute urinary retention (AUR); is a proven but rare condition in females. Imperforated hymen, which is found in 0.05-0.1% of females, obstructs blood flow at the onset of mensuration with a resultant hematometrocolpos presenting most commonly with abdominal pain and urinary symptoms in the background of primary amenorrhea, which is similar to the presentation of the 11 years old female in the case report. She had abdominal pain and dysuria, which AUR followed for 16 hours. The patient was at Tunner stage 3, and the examination revealed a palpable tender pelvic mass up to the umbilicus level with a bulging introitus and an imperforated hymen. Ultrasonography confirmed hematometrocolpos and an associated bilateral grade 2 hydronephrosis. Therefore, hymenotomy and excision of hymenal edges were done. Although diagnosis can be directed by physical examination, it can be significantly delayed or missed due to generally low incidence rate and insufficient physical examination due to cultural and religious reasons. This case report directs toward the importance of high clinical suspicion of hematometrocolpos as a cause of AUR in adolescent females and the necessity of a complete detailed physical examination, although it is rare.