The authors report 38 consecutive cases of histologically proved breast radial scars (RSs) detected at mammography. In a retrospective review of mammograms in 30 matched cases of nonpalpable RS and nonpalpable scirrhous cancer, the characteristic mammographic features of RS were confirmed: (a) the absence of a central opacity, often substituted by a radiolucent area; (b) the presence of multiple elongated thin spicules radiating from the center of the lesion; (c) the infrequency of any palpable finding, even for superficial lesions of relatively large size. Microcalcifications with aspecific structure were found in the lesions on mammograms of 14 of the 38 cases and in 24 of the histologic specimens. The typical mammographic features of RS were not specific to RS, being present in a minority of cancer cases. For two blinded readers, sensitivity was 86.7% and 76.7% and specificity was 78% and 80%, respectively. Although some specific mammographic features may suggest the presence of RS, the final differential diagnosis from scirrhous cancer should be based on histologic evidence, and surgical biopsy should be advised for any stellate lesion detected at mammography.