PURPOSE: To evaluate the impact of hypofractionated boost after hypofractionated whole breast irradiation in breast carcinoma. METHODS AND MATERIALS: Patients after breast conservative surgery were treated all time with hypofractionation of 2.67 Gy/day. Whole breast dose was 40.05 Gy followed in case of risk of local relapse by a boost of 16.02 Gy or 8.01 Gy. Acute and chronic toxicity results were evaluated including cosmetic software-assisted assessment and objective evaluation of fibrosis parameters (elasticity and hydration) by means of a skin tester. RESULTS: A total of 362 patients were evaluated. Acute toxicities comprised grade 1 dermatitis in 48.1 %, grade 2 in 44.5 % and grade 3 in 17 patients 4.7 %, respectively. After a median follow-up of 4.5 years, in 308 cases (86.6 %) there was no chronic skin or subcutaneous changes. In the first consecutive 50 patients, measures with skin tester showed no statistical differences in parameters for skin and subcutaneous fibrosis. Cosmetic results were considered excellent and good in 26 and 62 %, respectively. CONCLUSIONS: Boost to tumour bed with hypofractionated doses is well tolerated and acute and chronic toxicities are mild with good cosmetic results. Objective systems are encouraging methods to assess skin quality and cosmesis.