This chapter provides an in-depth illustration of the most common uterine neoplasms – smooth muscle tumors. Primary entities including leiomyoma, smooth muscle tumors of uncertain malignant potential, and leiomyosarcoma are extensively detailed, encompassing their histopathologic, immunophenotypic, and molecular profiles. Within the leiomyoma section, the salient features of each different leiomyoma variant are elaborated. These include mitotically active leiomyoma, cellular leiomyoma, highly cellular leiomyoma, epithelioid leiomyoma, myxoid leiomyoma, dissecting leiomyoma, lipoleiomyoma, angioleiomyoma, intravenous leiomyomatosis, benign metastasizing leiomyoma, and disseminated peritoneal leiomyomatosis. This is followed by a comprehensive discussion of leiomyosarcoma and its variants, such as epithelioid leiomyosarcoma and myxoid leiomyosarcoma, highlighting their key clinicopathologic features, diagnostic pitfalls, differential diagnosis, immunoprofile, and the most updated molecular features. Smooth muscle tumors of uncertain malignant potential and atypical leiomyoma (leiomyoma with bizarre nuclei) will be discussed at the end of the chapter. Fumarate hydratase-deficient atypical leiomyoma is specifically addressed in the atypical leiomyoma section. Overall, this chapter serves as a comprehensive resource, merging clinical, histopathological, and molecular perspectives to deepen the understanding of these common yet intricate uterine smooth muscle tumors.