Abdominal pregnancy occurs in one out of 10,000 deliveries. Omental ectopic pregnancy is the least common of these pregnancies and diagnosis is generally made during laparotomy. We report the case of a 28-year-old woman, secundigesta, secundípara, who presented with menstrual delay, cutaneous-mucosal pallor, and severe abdominal pain. During laparotomy, the presence of omentum was observed in the pelvis and uterus. Both adnexa were normal. A tumor was found on the inferior border of the omentum. The tumor was removed and partial omentectomy was performed. A primary omental ectopic pregnancy was diagnosed.