Ovarian pregnancy is a rare variant of ectopic implantation. A case of an intrafollicular ovarian pregnancy after ovulation induction/intrauterine insemination is presented. The woman had primary infertility of 4 years. Diagnostic laparoscopy revealed endometriosis and adhesions. After adhesiolysis and laser vaporization of endometriotic implants, the patient underwent ovulation induction with artificial insemination by husband/intrauterine insemination; she conceived at her second attempt. The pregnancy proved to be an ovarian intrafollicular one. She was treated by right partial ovariectomy. Three months later she conceived spontaneously with an intrauterine pregnancy which is still ongoing. The diagnostic problems resulting from the coexistence of ovarian hyperstimulation and the intrafollicular development of pregnancy are discussed. A re-evaluation of the criteria for the diagnosis of ovarian pregnancy based on the currently available diagnostic methods is proposed. Moreover, the pathophysiology of ovarian and especially intrafollicular implantation is reviewed.