Ovarian sex cord-stromal tumors represent approximately 7% of all ovarian tumors and are distinguished by their histopathologic diversity and hormonal activity (Al Harbi R, McNeish IA, El-Bahrawy M, Int J Gynecologic Cancer. 31:161–168, 2021). These tumors arise from primitive sex cords or stromal cells and encompass a variety of cell types, including theca cells, fibroblasts, Leydig cells, granulosa cells, and Sertoli cells (Al Harbi R, McNeish IA, El-Bahrawy M, Int J Gynecologic Cancer. 31:161–168, 2021). They are notable for their potential to produce hormones like androgens, estrogens, and corticoids, leading to various clinical syndromes ranging from virilization to hyperestrogenic symptoms (Al Harbi R, McNeish IA, El-Bahrawy M, Int J Gynecologic Cancer. 31:161–168, 2021; Sertic M, Devins KM, Oliva E, Lee SI, Kilcoyne A, Radiol Clin North Am. 61:595–608, 2023). The World Health Organization’s classification for these tumors has recently been updated, dividing them into pure stromal tumors, pure sex cord tumors, and mixed sex cord-stromal tumors (Al Harbi R, McNeish IA, El-Bahrawy M, Int J Gynecologic Cancer. 31:161–168, 2021; Sertic M, Devins KM, Oliva E, Lee SI, Kilcoyne A, Radiol Clin North Am. 61:595–608, 2023). The majority of these tumors present as low-grade diseases in younger patients and follow a nonaggressive clinical course, typically managed through surgical intervention. Given their benign nature, prognosis is generally favorable. The chapter describes the importance for radiologists to be familiar with ultrasonography, computed tomography, and magnetic resonance imaging features of these tumors to aid in differential diagnosis. This knowledge is critical in improving diagnostic accuracy and in guiding appropriate surgical planning, thus avoiding unnecessary treatments.