We present a case of atresia hymenalis in a 12.5 year old female who was admitted to gynecological emergency with a history of severe lower abdominal pains over the course of a few months. Provided are clinical pictures of the “Pseudoacute abdomen”. Upon clinical examination, we found blue, shiny, bulging and imperforated hymen. An abdominal mass was palpated in the vicinity of the navel. Transabdominal ultrasound demonstrated mass filled with thick liquid. “Mercedes hymenal incision” was performed in general anaesthesia. About 1.2 litre of dark, thick blood was removed. Postoperative course was uneventful. The two years of follow-up were characterized with regular psychomotoric development for the age with regular menstrual cycles.