Sertoli -Leydig cell tumor (SLCT) is a rare variety ovarian tumor that belongs to the group of sex-cord stromal tumors. These constitute less than 0.5% of malignant ovarian tumors. A recurrence of Sertoli-Leydig cell tumor of right ovary in a 21-year-old pregnant woman with twenty weeks pregnancy is reported. Oligo-menorrhoea, obesity, mild hirsutism and other features of virilism were associated with the condition. Normal level testosterone and alpha-fetoprotein (AFP) were found preoperatively.Exploratory laparotomy and right sided salpingo- ovariotomy was performed in fifth month of pregnancy, under general anaesthesia. There were no pelvic or peritoneal metastatic deposits. Histopathology and immuno-histo chemistry confirmed the diagnosis of poorly differentiated Sertoli- Leydig cell tumour. Onco-surgeon and physician were consulted for tumor surveillance and further management during pregnancy. It was decided to start cancer chemotherapy after the delivery of baby. After the laparotomy ,patient had uneventful antenatal period .She was delivered by an elective caesarean section at the completion of 38 weeks. A healthy male baby with 3 kg birth weight was born with good Apgar score and without any congenital malformation. Peritoneal metastatic deposit of 3 to 4 cms in size were found in the pelvic region during caesarean section .These tumour deposits were removed during caesarean section and sent for histopathology .Histopathology report was suggestive of poorly differentiated Sertoli- Leydig cell tumour. Patient was treated with paclitaxel and carboplatin regemen in the postpartum period. This is one of the rare reports on a Sertoli- Leydig cell tumor which showed recurrence and rapid growth during pregnancy.