To determine the clinical and mammographic features of recurrent breast cancer after tumorectomy and radiation therapy, the authors reviewed the clinical history and serial mammograms of 48 patients with suspected recurrence. Of patients with recurrent disease, seven had positive mammograms alone, nine had positive findings at physical examination alone, and eight had both positive mammograms and positive results of physical examination. Positive mammographic findings included the development of new fine calcifications (six patients), a new mass (five patients), mass and calcifications (one patient), increasing opacity (two patients), or skin thickening (one patient). Patients in whom the breast recurrence was detected mammographically alone were less likely to develop metastatic disease in subsequent follow-up than when results of physical examination were positive at the time of breast recurrence. Serial mammographic and clinical examinations are complementary for optimal detection of recurrence after conservative surgery and radiation therapy.