Abstract The effects of laser irradiation on are of great interest, as they allow for the optimization of hyperthermia treatment. Thermal effect of laser radiation is now used routinely in surgery to incise, coagulate, or vaporize tissues. The laser irradiation power is converted into heat in the target volume with resulting coagulative, necrosis, secondary degeneration and atrophy, and tumor shrinkage with minimal damage to surrounding structures [1]. Accordingly, the main purpose of this study is to develop a finite element model to simulate the laser distribution through the tumor tissue and the heat transfer due to this laser irradiation. Also, we studied the effects of varying laser intensity and cooling conditions at the breast surface. This can be achieved by using finite element models using COMSOL Multiphysics (FEM lab) software