Abstract This study aims to compare proton therapy and Proton Boron Capture Therapy (PBCT) through Monte Carlo simulation. A proton beam passing through the Snyder head phantom was simulated with and without boron in a tumor region at the center of the phantom. To evaluate the interaction between protons and boron, the simulation was carried with varied boron concentrations in the tumor and different proton energies. With boron accurately used in the tumor region, the Bragg peak value of the maximum dose level increased as the boron concentration increased, and there was a change in the depth of the peak. As it emerged through calculations, the use of protons associated with boron in the phantom was more efficient than proton therapy in the tumor region. It was also observed that the increase of 11B concentration could enhance the dose of secondary alpha particles in the tumor region, compared to proton therapy. The dose of these particles decreased as the energy increased. It was found to be 4 at the proton energy of 110 MeV and 1 at 118 MeV with and without boron respectively. The effectiveness of PBCT indicated through Monte Carlo simulation proves it as a potential method to be used in radiotherapy.