Objective To investigate CT and MRI features of ovarian theca-fibroma. Methods The clinical data of 52 cases of ovarian theca-fibroma treated in our hospital from January 2015 to January 2017 were analyzed retrospectively. All patients underwent CT and MRI examinations. Results Premenopausal symptoms of 7.69% were irregular menstruation with high volume. Only 1.92% did not have any clinical symptoms. The clinical postmenopausal symptoms were various without settled regularities, while most people had abdominal pain and discomfort. 82.69% of patients had elevated CA125, while the patients without CA125 detection accounted for 5.77%. There were 61 tumors in 52 patients, of which 96.72% were single, and the other 3.28% were connected to the same side. The lesions on the left side accounted for 42.62%, and the right side accounted for 54.10%. The average diameter of ovarian thecoma and ovarian fibrothecoma was (10.59±1.58)cm and (5.69±1.59)cm, respectively. A total of 54 lesions were detected by CT with 98.15% of homogeneous focus and 1.85% of heterogeneous focus. The solid part showed low signal or equal signal, while the rest of the tumor images showed uneven signal with different degrees of cystic degeneration. A total of 60 lesions were detected by MRI including 36.67% of ovarian thecoma and 63.33% of ovarian fibrothecoma. T2WI showed that the edges of the tumor were blurred with an uneven cloud-like high signal. 51.67% of ovarian fibrothecoma had homogeneous signal on T1WI, of which 711.67% had patchy hypointensity. T2WI below the mass was a low signal. The lesions in the arterial phase were not obviously enhanced. The lesions in the venous phase were irregular stripe, no enhancement in the cystic area was found after further enhanced in the parenchymal phase, but a uniform thin film was seen. The high signal was found in the interstitial edema and tumor internal capsule with "mountain clouds" signs. Conclusion Accurate analysis of CT and MRI imaging features can significantly improve the detection rate of ovarian theca-fibroma, and the CT image is characterized by low signal, low density and round like shape, while the MRI features are high signal on T1WI and low signal on T2WI with "mountain clouds" signs.