The present work seeks to present what is the Monte Carlo Simulation and how it can be applied in the predictability of an investment fund s return, possibly aiding in the creation of a retirement plan. The motivation for the elaboration of this work is the current difficulty encountered by professionals acting in the financial market, when aiming to replicate uncertainties present in a volatile Market for the future. In the present day, we can observe a bigger interest in the Brazilian population (even if it is still small compared to other more developed nations) in seeking financial education. Taking this into account, with the assistance of statistic and probabilistic tools, coupled with the gathering of historical data, the applicability of the Monte Carlo Method in a financial plan was analyzed. Throughout the study, Microsoft Excel tools were utilized, as well as historical data concerning the profitability of some of the Brazilian s stock market most traditional investment funds, consulted through the use of a comprehensive database. The results obtained via the Monte Carlo Method were dissected and analyzed, assisting in finding a conclusion as to how assertive and applicable the Monte Carlo Method truly is in the studied context.