We report two cases of cholesterol granuloma of the breast clinically diagnosed as malignant and describe the features. The first patient was a 74-year-old woman who complained of a lump in the left breast. The mammography and ultrasonography suggested a malignant mass. Fine needle aspiration showed multinucleated giant cells. We suspected breast cancer, but cholesterol granuloma was diagnosed on excisional biopsy. The second case was a 51-year-old woman who was found to have a breast tumor on a screening mammography. The mammography and ultrasonography suggested carcinoma, but excisional biopsy revealed cholesterol granuloma. Reports of cholesterol granuloma of the breast are very rare. Cholesterol granuloma should be considered in the differential diagnosis of breast carcinoma.