The pair 133La/135La presents considerable potential for theranostic applications in nuclear medicine. Consequently, the implementation of a simulated production process for 133La/135La is crucial to identify a cost-efficient approach. This study utilized the Monte Carlo method to simulate and assess the bombardment parameters and production conditions for generating 133La/135La via a proton cyclotron. Three barium target materials, natBaCO3, natBa metal, and 135BaCO3, were examined for 133La/135La yields. The impact of proton energy, cooling time, and target thickness on the 133La/135La yields were assessed utilizing TALYS, FLUKA, and SRIM software. The results indicate that the proton energy range necessary for attaining elevated yields of 133La and 135La in natBaCO3 and natBa metal targets is 23-24 MeV, with the optimal energy being 23.9 MeV. For the 135BaCO3 target, the proton energies required for 133La and 135La are approximately 30.2 MeV and 12.8 MeV, respectively. A cooling time of 2-3 h is advised for the natural barium target, whereas 1-2 h is appropriate for the 135BaCO3 target. The highest yield is attained when the target thickness approaches the proton range. The practical and accurate application of this simulation for designing and optimizing radionuclide production is corroborated by the alignment of experimental and simulation results.