Benign ovarian serous tumors are lesions comprised of benign tubal type epithelium and varying proportions of stromal and cystic components. In rare instances, benign ovarian serous tumors can also contain a minor component of sex cord-stromal elements. The authors describe the case of a 59-year-old postmenopausal woman presenting with a right ovarian mass, that upon resection and examination of permanent sections, was appreciated to predominately be a serous cystadenofibroma. Additionally, there were cords and focal sheets of sex cord-stromal elements, that by immunohistochemical staining, were positive for calretinin and inhibin. The histomorphologic and immunophenotypical features supported that the ovarian tumor was a serous cystadenofibroma with sex cord-stromal elements: this being the second description in the literature to date. While there is a paucity of prognostic data on benign ovarian serous tumors with sex cord-stromal elements, the benign histologic features suggest a favorable outcome for patients, as one would expect with any surgically resected counterpart lesion devoid of sex cord-stromal elements.