Primary ovarian ectopic pregnancy (OEP) remains a rare but important type of ectopic pregnancy which is normally diagnosed at surgery. The aetiology is unknown. We have found fertility treatments (18.1%) and intrauterine contraceptive devices (19.3%) remain important associated risk factors. We undertook a world literature review of all cases since 1995. We found that 52% of cases were managed laparoscopically, which is less than the reported UK rate of all ectopics, of 85.9%. Over that time period, eight patients were treated medically with a success rate of 50%. While the original 1878 Spiegelberg's criterion still holds for the diagnosis, the addition of modern ultrasound scanning has made a radiological diagnosis possible. In a few cases, the management of OEP remains similar to that of a tubal ectopic pregnancy with the same challenges. Laparoscopy with ovarian sparing in the stable woman is today the surgical treatment of choice.