Sclerosing stromal tumor of the ovary is a rare ovarian disease with prevalence of 1.5% to 6% of ovarian stromal tumors. We present a 24-year-old woman with irregular menstruation for 6 months and a self-palpable lower abdominal mass. Enucleation of the left ovarian tumor was undertaken. Gross examination showed a soft elastic tumor with a smooth outer surface and diffusely white edematous stroma with scattered yellowish nodular areas on the cut surface. Histologic study showed that the cellular nodules consisted of a disorganized admixture of fibroblasts and round vacuolated tumor cells. The cellular nodules were separated by edematous hypocellular fibrous tissue forming a pseudolobular appearance. Regular menstruation resumed after the surgery and no evidence of tumor relapse during 1 year of follow up.