We model the effects of the cryosurgery process for prostate cancer in COMSOL Multiphysics® (ver 5.1) using imaging and manufacturing data to generate 3D realistic geometry for the prostate and cryoprobe. By imposing a freezing temperature at the probe-tumor boundary, we can observe the impact on healthy tissue over the freeze-thaw cycles of the surgery procedure. By varying the number and locations of probes, as well as the rate of the freeze-thaw cycle, we find the optimum cryosurgery procedure that kills as much cancer as possible while minimizing damage to the remainder of the prostate. We find that, for an “average” spherical tumor roughly 1 cm in radius found in the center of the prostate, a single probe piercing the tumor’s center fully treats the cancerous tissue without harming healthy tissue more than 1 mm away from the tumor’s edge. This assumes two freeze-thaw cycles at -196°C. This proves that the simulation methodology can predict the optimum surgery procedure. With proper imaging data, this same procedure can be used to treat individuals with differently-shaped and oriented prostate tumors.