Review of medical records revealed 29 women with biopsy-proved mammary angiosarcoma evaluated at the authors' institution from 1966 to 1991. The women ranged in age from 20 to 70 years (mean, 42 years). All presented with a palpable mass. Five of 29 (17%) had overlying bluish skin discoloration. Mammographic findings, available in 21 cases, included solitary uncalcified mass in 11 (52%) patients, mass with calcifications in two (10%), mass with associated skin thickening in one (5%), and no findings in seven (33%). Ultrasound, performed in five cases, revealed a solitary solid mass in three patients, multiple solid masses in one, and no findings in one. In the only case in which it was performed, magnetic resonance imaging revealed a mass with low signal intensity on T1-weighted images but higher signal intensity on T2-weighted images. Patients with higher-grade lesions at pathologic evaluation were significantly (P less than .05) more likely to have abnormal mammograms and to develop recurrent disease.