We report a case of successful myomectomy in pregnancy. The patient, a 27 year old nulliparous, presented with 2 year history of progressive abdominal swelling and 13 weeks of amenorrhoea. Abdomino-pelvic ultrasonography revealed a viable intrauterine pregnancy at 18 weeks and 3 days; there was also a huge mass with cystic component, extending from the pelvis to the whole of the abdomen, with associated dilatation of the renal calyces bilaterally; sonographic diagnosis of ovarian mass in pregnancy was made. At exploratory laparotomy, a huge subserous leiomyoma coexisting with pregnancy was found; myomectomy was done. The rest of the pregnancy was uneventful, and the patient had spontaneous vertex delivery of a live infant at term.