Both ultrasonography and x-ray mammography were performed on a male patient who had breast carcinoma. While the x-ray mammographic features were highly suggestive of malignancy, the sonographic findings were subtle. Because of the technical difficulties associated with x-ray mammography of the male breast, ultrasound has been advocated for the evaluation of gynecomastia and breast masses in men. A review of both the ultrasound scans and x-ray mammograms obtained over a three year period of 41 men who had breast enlargement shows the two modalities to be complementary. There was overlap in the appearance of benign and malignant disease on images of each modality alone, and the use of both modalities in the examination of each patient is believed to improve diagnostic accuracy.