Seventy-one ductal carcinoma in situ (DCIS) patients were reported to the tumor registry at the National Naval Medical Center between 1986 and 1995. This number represents 6.5% of all breast cancer patients. We did not include the patients with microinvasion or infiltrating ductal carcinoma with extensive DCIS in this study. After excluding 16 cases because of inaccessable clinical records, 55 cases of pure DCIS were analyzed. The mean age at presentation was 52.0 years (32 year-old to 74 year-old) and the most common clinical feature was an abnormal mammographic finding (40 cases, 73%). Family history of breast cancer was positive in 14 cases among the 39 cases with DCIS (35.9%) according to the medical records. Total mastectomy was the most common form of treatment for DCIS (19 cases, 34.5%) during this period, followed by modified radical mastectomy, lumpectomy only, lumpectomy with radiation therapy. Three hundred and two axillary lymph nodes were examined but revealed no nodal metastasis. Comedo type DCIS was the most common subtype (21 cases, 38.2%). There were no local recurrences or DCIS related deaths reported to the tumor registry during this period (mean follow-up interval of 51 months).