The aim of the study was to investigate the mediating effect of critical thinking on the relationship between job characteristics (skill variety, autonomy and participative decision making) and achievement goal orientations. The research model was tested with 296 participants (164 male and 120 female), who worked in health, security, education and public sectors; in Marrakech, Rabat and Casablanca. The survey consisted of five sections: The explanation; job characteristic, critical thinking and achievement goal orientation items and demographic questions. SPSS 16 program was used to make statistical analysis of the data.