Patients with isolated locoregional breast cancer recurrences should be treated with curative intent. Mastectomy is regarded as the standard of care for patients with ipsilateral breast tumor recurrence. In a selected group of patients, partial breast irradiation after second breast-conserving surgery is a viable alternative to mastectomy. If a second breast conservation is performed, additional irradiation should be mandatory, especially in patients who had not been irradiated previously. In case of re-irradiation, the largest experience exists for multi-catheter brachytherapy. Prospective clinical trials are needed to clearly define selection criteria, long-term local control, and toxicity. In patients with resectable locoregional breast cancer recurrences after mastectomy, multi-modal therapy comprising complete resection, radiation therapy in previously unirradiated patients, and systemic therapy results in 5-year disease-free and overall survival rates of 69% and 88%, respectively. In radiation-naive patients with unresectable, isolated locoregional recurrences, radiation therapy is mandatory. In selected patients with previous irradiations and unresectable locoregional recurrences, a second irradiation as part of an individual treatment concept can be applied. The increased risk of severe toxicity should always be weighed up against the potential clinical benefit. A combination therapy with hyperthermia can further improve the treatment results.