This paper seeks to define the process for the continuous evaluation of the financial benefits during Six Sigma project life time. The financial criteria are critical success factors of a Six Sigma project. The process has been developed as part of the six sigma project monitoring in order to estimate proper allocation of the resources taking in account the expected project benefits as well as evaluationof real achievements. The evaluation of the finacial benefits based on the quality costs is not sufficient in the real life and has to be accomplished with key financial performance indicators of the business to visualize the results. The evaluation based on the savings seems to be too difficult especially for green belts. The early involvement of the finance department in the project definition as well as ongoing evaluation is key. The defined process has been applied to real business enviroment.