Local recurrence following breast-conserving surgery for breast cancer is a significant failure of local treatment. This article reviews the mechanisms, risk factors and overall significance of such local recurrence. The presence of disease at excision margins, an extensive intraduct component, lymphatic vessel invasion, tumour grade and tumour size are currently the best predictors of risk for local recurrence. Early local recurrence is due to residual disease and is associated with both decreased distant disease-free survival and overall survival; it appears to reflect aggressive biological characteristics of the primary tumour. The importance of adequate local treatment for breast cancer is discussed.