Purpose: Today, organizations work hard to improve the motivation of their employees and related knowledge, skills and abilities to enhance work performance. Among many other variables, self-efficacy proved to have an influential role in work performance. The main purpose of the current study is to investigate the role of occupational self-efficacy on work performance through intrinsic motivation by using a longitudinal analysis. Design/methodology/approach: Participants were 76 employees from diverse organizations operating in an organized industrial region in Turkey. Participants filled in a weekly questionnaire during ten consecutive weeks. Findings: Results of multilevel analyses confirmed our hypotheses by showing that occupational self-efficacy and intrinsic motivation have a significant influential role over work performance, and intrinsic motivation serve as a partial mediator in this relationship. Originality/value: The study findings also reveal important information for organizational and managerial practices to improve employee motivation and performance.