Background: Accelerated hypofractionated approach is based on the radiobiologic model that a lower total dose delivered in fewer, larger fractions over a shorter period of time is at least as effective as the traditional longer schedule with increasing evidence of equivalent efficacy and toxicities from randomized trials comparing conventional radiotherapy schedules to different hypofractionated schedules. Patients and methods: 100 female patients having breast cancer after finishing their chemotherapy if indicated, randomized into two arms of accelerated hypofractionation; 39Gy/13 fractions (group A) and 42.4Gy/16 fractions (group B) both regimens given as 5 fractions per week. Results: The disease free survival was 93% and local recurrence was 1%. There were no statistically significant effects as regards recurrent rate in any studied factors. Radiation complications of patients, in terms of skin, subcutaneous, pulmonary, cardiac, ipsilateral arm lymphedema and brachial plexus toxicity, were assessed and graded in both group A and group B. There was significant increase of incidence of acute radiation dermatitis in patients receiving 39 Gy, as grade I and II reported in 82% and 46% for 39 Gy group and 42.4 Gy group respectively. In-addition, increased chronic subcutaneous fibrosis among patients with group A (28%) in comparison to group B (18%) that reach statistical significance. Type of surgery is the only factor that had significant effect on incidence of acute radiation dermatitis and chronic subcutaneous fibrosis. Conclusion: Our study concluded Equivalent efficacy of 39 Gy in 13 fractions and 42.4 in 16 fractions regarded local control and survival. 39 Gy in 13 fractions is not recommended for patients underwent BCS.