A fuzzy evaluation system to decide critical students' final marks is presented. The marks of the assessment tests made by students along the academic year are transformed into linguistic terms and used for assigning values to linguistic variables. Subjective criteria as i.e. student's interest or student's progression are used in order to decide whether every analyzed student passes or fails the considered subject. This paper presents the features of the subject where the fuzzy system has been applied in, the proposed fuzzy decision system, and results when it is applied using real students' marks.