Six hundred seventy-six patients with ductal carcinoma in situ of the breast (DCIS) from 1971 to 1995 were included in the study. Computerized patient files were retrospectively analyzed. Clinical findings were less frequently reported to reveal DCIS after 1989. Positive mammographic findings were obtained in 87% of patients and were mainly represented by microcalcifications (79.4%). Treatment procedures were breast-conserving surgery (BCS) alone (37.5%), BCS followed by radiation (BCSR) (25.5%), or mastectomy (M) (37%). The actuarial local recurrence was 2.6% in the M group (94 months of follow-up), 14.5% in the BCS group (85,7 months of follow-up), and 7.5% in the BCSR group (78.8 months of follow-up). Predictive factors of recurrence in all patients were invaded margin status and age. In the BCS group, grade was also a predictive factor. The analysis per decade shows that the lesions currently diagnosed are less serious than those of the past. All the recurrence in patients with positive margins was in the same quadrant as the original lesion. This further emphasizes the need for clear margins.