Catamenial pneumothorax is a rare condition that is often misdiagnosed. It is defined as spontaneous pneumothorax occurring within 72 hours before or after onset of menstruation. Etiology is unknown but could be linked to endometriosis. Pleural ablation via thoracoscopy and hormonal therapy are mainstay treatment options to avoid recurrence. We present a case of a young adult female who experienced gradual painless abdominal distention that resolved spontaneously after each menses twelve years post menarche. She was first seen at a peripheral facility where laparotomy undertaken was negative for suspected ectopic pregnancy. However, a bleeding omental mass was noticed and a biopsy taken. Histopathology reported it as an endometriotic tissue. The patient subsequently had recurrent cyclical chest pains and breathlessness leading to the diagnosis of catamenial pneumothorax. She had chemical pleurodesis done with sterile talc after chest tube drainage and has been well over two years now.