This article summarizes the modern evidence-based management of ductal carcinoma in situ. The data addressing the surgical issues, including indications for mastectomy and the use of sentinel node biopsy, are presented. The randomized trials examining the role of radiation therapy after breast-conserving surgery and the use of tamoxifen in ductal carcinoma in situ are discussed. Factors to consider in developing a management strategy for the individual patient are elucidated in the final section.