It is a critical issue for the continuity of an organization to efficiently evaluate the performance of its employees. The evaluation process has to guarantee a sufficient level of objectivity and a limited level of subjectivity in order to answer the employees' expectancies. In this study, a multi-criteria approach to this problem has been proposed since the employees' performance depends on various criteria simultaneously. It is also considered that those criteria may have interaction. Hence, Choquet Integral has been used to handle this situation. To illustrate the use of the proposed method, the performance of a set of employees working in a company in medical sector is evaluated.