Omental pregnancy is a rare form of ectopic pregnancy, and can be seen primarily or secondary to a tubal pregnancy. A 25-year-old woman presented with abdominal distention with pain and anemia without vaginal bleeding. After a provisional diagnosis of ruptured ectopic pregnancy, laparotomy was performed. On surgical exploration, the bilateral tubes and ovaries were intact, however, an omental pregnancy was detected as the cause of hemoperitoneum. Partial omentectomy was performed. Although most cases are secondary, presented here is an additional case of primary omental pregnancy at 12 weeks according to Studdiford's criteria. Histological evidence of neovascularization into the supporting tissue confirmed our diagnosis. A primary omental pregnancy should always be considered as a possible explanation for severe hemoperitoneum in ectopic pregnancies presenting with acute abdomen, and with intact adnexes on surgical exploration.