We examined the effect of delaying radiation treatment after conservative surgery on the risk of breast cancer local recurrence (LR). From January 1997 to December 2001, 969 women with early-stage breast cancer were treated at the Radiation Oncology Department in Chieti. We analyzed 802 of them who underwent conservative surgery followed by whole-breast radiotherapy. The patients were divided into two groups: women who did not receive chemotherapy and women who received chemotherapy. The time intervals from surgery to breast irradiation used for the analysis were <16 or more weeks for no-chemotherapy-treated women, and <25 and 25 or more weeks for chemotherapy-treated women. The relationship between LR and factors such as age, tumor size, margin status, and surgery-radiotherapy time interval was evaluated. The 8-year LR risk was estimated using the Kaplan-Meier method. LR was observed in 33 (4.1%) of the 802 patients. The overall 8-year LR risk was 6.5% (+/-1.51). In the no-chemotherapy group, the risk of LR was associated with a younger age and a positive margin status. In the chemotherapy group LR was associated with a younger age and a tumor size >3 cm. Surgery-radiotherapy interval was not associated with LR in both groups of patients. Delay in the start of radiotherapy does not increase the risk of LR in patients with early breast cancer treated or not treated with chemotherapy.