A theoretical process-oriented model of affective organizational commitment is presented to explain the psychological mechanisms that may trigger individuals' affective commitment to their organization. An operational version of the model is tested, along with several theoretically based alternative models, using meta-analytic correlations and structural equations modelling. Results suggest that intrinsic motivation is a partial mediator of the relationship between several exogenous variables (job characteristics and work context variables) and work attitudes (affective organizational commitment and general job satisfaction). In addition, affective commitment and general job satisfaction are related to turnover behaviour, whereas only affective commitment is related to absenteeism. Implications for theory and applied research are discussed.