Ovarian yolk sac tumors are malignant germ cell tumors of young women that exhibit a range of histologic growth patterns that may mimic several other primary and secondary ovarian tumors. Reticular, endodermal sinus, polyvesicular-vitelline, hepatoid, and glandular architectures represent the chief morphologic patterns. Secondary features include Schiller-Duval bodies and hyaline globules. α-Fetoprotein expression, both serologic and immunohistochemical, characterizes this tumor. This review focuses on the distinction of yolk sac tumor from its main mimics, including clear cell carcinoma, endometrioid carcinoma, embryonal carcinoma, sex cord–stromal tumors, melanoma, and hepatocellular carcinoma.