We performed CT-guided percutaneous uterine biopsy in three females for whom diagnosis by endometrial brushing cytology and endometrial biopsy had proved difficult. In each case, a percutaneous tumor biopsy was performed using CT fluoroscopy with reference to the MR images obtained beforehand. The sampling of multiple biopsy specimens was successful by the coaxial method using a 16/18G Quick-Core biopsy needle in all the cases, and definitive histopathologic diagnoses were achieved. The final pathological diagnoses were one benign lesion (pseudowidening of adenomyosis) and two malignant lesions (small cell carcinoma and adenocarcinoma of Mullerian origin of ovaries). There were no associated complications. The treatment strategy was formulated according to the results of the pathological diagnosis in each case, and consisted of either hormonal therapy or systemic chemotherapy.