Ovarian tumors present a special diagnostic challenge when imaging findings cannot be categorized into benign or malignant pathology. Magnetic resonance imaging (MRI) is currently used to evaluate ovarian tumors. The aim of this study was to evaluate the diagnostic performance of MRI in patients with benign or malignant ovarian tumors and enhance its diagnostic accuracy. The MRI findings of 48 cases of ovarian tumors, which were confirmed by surgery or pathology from September 2009 to July 2011, were analyzed retrospectively. T1-, T2-, and fat-suppressed T2-weighted sequences were performed and dynamic contrast-enhanced T1-weighted gradient-echo images were performed after IV injection of Gd-DTPA by 1.5-T unit. The ovarian tumors were examined for several features including size, bilaterality, shape, content (solid–cystic), signal intensity, and enhancement. Secondary signs such as ascites, peritoneal disease, and lymphadenopathy were noted. The imaging features with the surgical and pathologic findings were compared and the MRI features of benign and malignant ovarian tumors were compared and summarized. MRI features of 33 cases of malignant ovarian tumors were cystic-solid or solid masses, with irregular wall, and intense enhancement. MRI features of 15 cases of benign ovarian tumors were cystic masses, with regular wall, and not or slightly enhanced. The differences of bilaterality, shape, content (solid–cystic), signal intensity, and enhancement between benign and malignant ovarian tumors were statistically significant (p < 0.01). The data demonstrate MRI features may help differentiate benign ovarian tumors from malignant ovarian tumors.