In a globalized and competitive world, given the many possibilities of capital allocation and inherent economic uncertainties in investment decisions, the selection of profitable projects is an element of fundamental importance for companies’ success. The traditional methods for investments valuation, such as discounted cash flow (DCF), have been being criticized for not capturing adequately projects flexibilities. The advantages of including management flexibility and more frequent use of the real options theory in the evaluation of projects allow us to expand the theoretical discussions of the methods used for valuation. This study aims to apply the least squares Monte Carlo (LSM) method in economic valuation of upstream oil projects. For calculating real options with the LSM, a program in VBA (Visual Basic for Applications) language was built. Besides calculating the options value, it lets you run a sensitivity analysis. To validate the method, the analytical solution of Bjerksund & Stensland was used, as it is one of the most used in real options valuation and produces a graph of the optimal exercise for those options. In search for parameters to be used, a cash flow for an upstream oil project was simulated. Finally, the results can not be considered definitive; they can only guide the development and improvement of the use of LSM in Real Options.