Ovarian hyperstimulation syndrome (OHSS) is an entity arising in women undergoing assisted reproductive techniques (ART). The simultaneous presence of two different clinical complications such as OHSS and ectopic pregnancy (EP) is not frequent. The diagnosis of an extrauterine pregnancy can be obscured by the stimulated ovaries and ascites, and actually be missed, especially in women with increased body mass index. We report a case of a woman who presented with mild OHSS after in vitro fertilization (IVF), (intracytoplasmatic sperm injection (ICSI) and embryo transfer). The ectopic pregnancy was ascertained soon after by transvaginal ultrasound (TVS) and right salpingectomy was performed.