Prevalence of synchronous bilateral breast cancer (SBBC) is still scarce. No clear consensus to guide the specialists for best techniques to treat such complex target. Until now, 3DCRT considers an acceptable technique to treat SBBC in many cancer centers worldwide. This study will present the possible role of VMAT in treating SBBC in comparison with 3DCRT. All cases diagnosed and pathologically proven operable SBBC without any evidence of distant metastasis at our institution selected to this study. Eligible criteria are: patients are >18 years old with ECOG of 0-1 who resected all gross disease with level I to II axillary dissection with negative surgical margins and completed their adjuvant chemotherapy. We excluded Cases with metachronous bilateral breast cancer, treated with previous thoracic irradiation or have serious comorbid diseases, such as chronic obstructive pulmonary disease, connective tissue disease. We also excluded patients with postoperative wound infections, delayed wound healing, or treated with palliative intent. We delineated Planning target volumes (PTVs) and organs at risk (OARs) on the planning CTs. The dose prescribed for both plans is 50 Gy in 25 fractions+/- Boost of 10Gy over 5 fractions. We have collected a total of 9 cases with pathologically proven SBBC who were treated by adjuvant radiotherapy either post mastectomy/post conservative breast surgery in the period between January 2013 and December 2018. Indication of adjuvant treatment by radiation has been taken at our breast tumor board. The Averages of PTV coverage in VMAT vs. 3D-CRT were as following: D98%=45.9 vs. 44.2 Gy, D95%=47.3 vs. 46.1Gy, D50%=50.4 vs. 50.53 Gy, D2%=52.5 vs. 53.85 Gy, respectively. For organs at risk avoidance in VMAT vs. 3D-CRT were as following: heart V30=1.16 vs. 7.06 %, heart V25=3.66 vs. 7.75 %, Rt lung V5=98.3% vs45.64 %, Rt lung V20=12.73 vs. 25.45 %, Lt lung V5=98.30 vs. 45.64 %, Lt lung V20=10.70 vs. 23.70%, spinal cord Dmax= 16.86 vs. 7.97 Gy, Larynx Dmax=17.99vs 17.94, Larynx Dmean=6.40 vs 2.30 Gy, Esophagus Dmax=34.8 vs 5.20 Gy, Esophagus Dmean=15.60 vs 25.39 Gy, Dmean of constrictor muscles of the pharynx= 3.41 vs. 1.05 Gy, Liver Dmean=7.28 vs. 4.76 Gy, Stomach D100=3.22 vs. 0.57%, Thyroid Dmean=23.10 vs. 24.76 Gy, Thyroid Dmax=44.04 vs. 47.66 Gy, Rt humerus Dmean=14.19 vs. 17.27Gy, Lt humerus Dmean=14.14 vs. 17.15 Gy respectively. Our study revealed comparable results in regard of target volume coverage between VMAT and 3DCRT. The low dose to normal tissues is still considered as a real concern when VMAT used. In addition, VMAT was not adding much impact in terms of central structures avoidance. Hot spots outside the target volume and under coverage at fields junction is the most drawbacks when using 3DCRT. We might see some improvements in results of both techniques when using deep inspiration breath hold method along with them.