Spontaneous severe ovarian hyperstimulation syndrome-complicated natural pregnancy (SOHSSp) is a rare clinical entity and can be easily misdiagnosed as ovarian tumors. We report a case of SOHSSp in a 26-year-old women with successful delivery, and reviews the clinical data and the diagnosis and treatment of this case. The patient underwent a diagnostic laparoscopy and was followed-up for 1 year with a favorable prognosis.