Background: Sertoli-Leydig cell tumors (SLCTs), also known as arrhenoblastomas, are tumors of the sex cord-stromal group of ovary and testis cancers. They comprise <1% of all ovarian tumors. They are divided into 6 categories based on the degree of differentiation and the presence of heterologous elements. However, <15% of these tumors are poorly differentiated. Case: A 23-year-old unmarried female presented with an 8-month history of irregular menstrual cycle and abdominal pain. There were no clinical features suggesting virilization. The left salpingo-oophorectomy specimen revealed an oval ovarian mass of 11 × 7 × 4 cm in dimension. Grossly, the cut surface of the mass was yellowish white in color and solid in consistency and touch preparation was made. By applying cytology and immunocytochemistry techniques, a preliminary diagnosis suggestive of poorly differentiated SLCT was made. The tumor was confirmed as a poorly differentiated SLCT. Conclusion: Cytology and immunocytochemistry by WT-1, melan A, vimentin and calretinin are helpful in the diagnosis of poorly differentiated SLCTs.