Sertoli–Leydig cell tumor is a rather rare type of ovarian neoplasms belonging to the group of sex cord–stromal tumors. This malignancy is characterized by androgen overproduction, which results in the so-called virilization and can be accompanied by various metabolic disorders such as abdominal obesity, disturbances of carbohydrate and protein metabolism, and high blood pressure. During differential diagnosis, it is important to identify the source of androgen overproduction. An androgen-secreting ovarian tumor needs to be differentiated from androgen-secreting adrenal tumor, ovarian stromal thecomatosis (hyperthecosis), and endogenous hypercorticism (the Cushing’s syndrome). In most cases, the Sertoli–Leydig cell tumor is associated with DICER1 mutation carriership. If a patient is found to carry the DICER1 mutation, patient’s relatives need to undergo genetic testing as the individuals with mutations in this gene have an elevated risk of developing a broad range of benign and malignant tumors (most of these tumors are relatively rare in the overall population). The awareness of this rare ovarian neoplasm among medical specialists (obstetricians–gynecologists, endocrinologists, and oncologists) is supposed to ensure timely diagnosis and adequate treatment of this disease.