Radiation therapy treatment for post-mastectomy breast cancer usually requires a bolus to raise the surface dose to a certain level. Bolus is a compensatory material that has properties such as soft tissue or water. Therefore, this study will evaluate the potential of using bolus and without bolus in post-mastectomy breast cancer cases. This study aims to analyze the percentage surface dose (PSD) on the solid water slab phantom, dose-volume histogram (DVH), profile dose, and surface dose in Postmastectomy Radiation Therapy (PMRT) cases with and without using a bolus made of silicone rubber with a thickness of 0.5 cm. The methods used in the present study involving measuring surface dose using bolus and without bolus on a solid water slab phantom with the TRS 398 protocol, making an Intensity-modulated radiation therapy (IMRT) planning system in 5 fields with angles of 30˚, 60˚, 230˚, 260˚and 320˚. Then analyzed DVH, dose profile, and surface dose using bolus and without bolus. Finally, verification of the plans that have been made is done using EBT3 film placed at 3 points (isocenter, right, and left). The results showed that DVH with bolus and without bolus met the recommendations of the International Commission on Radiation Unit (ICRU) 62, and organ at risk (OAR) still met the tolerance limit. The percentage of surface dose reached 80.02 % and 29.75 %, respectively, for with and without bolus. The surface dose in PMRT increased up to 35%. Moreover, a bolus can increase the dose to the surface very well when the tumor cells are located on the surface compared to without a bolus.