Purpose: This study aims to examine the effects of using a personal development plan (PDP) on the undertaking of learning activities and the employee's job competencies. Design/methodology/approach: Data from Dutch pharmacy assistants was collected (n=2,271). Analyses of variance (ANOVAs) as well as regression analyses were conducted on this dataset. Findings: The results indicate that PDP users undertook more learning activities in the past than non-users, but using a PDP does not stimulate users to plan more learning activities in the future. Furthermore, PDP users do not score themselves significantly higher on job competencies than non-PDP users. Research limitations/implications: Future research should investigate the effectiveness of PDPs for the undertaking of learning activities and job competencies in a broader sample, involving multiple-raters and focusing more closely on one essential feature of the PDP practice: the feedback given by a supervisor and/or colleague or coach when discussing the PDP. Practical implications: The results stress the value of a PDP as a feedback tool. The tool could add significant value to the learning and development process of the pharmacy assistant, however, if it would be used as a feed-forward instrument as well. In other words, the tool should more often be used to get an overview of desired future plans, plan future careers, and the undertaking of learning activities in order to reach these future goals. Originality/value: In order to promote employees' learning and development, more and more companies are starting to implement PDPs. Empirical studies researching the effectiveness of PDPs in the workplace are scarce, however. (Contains 3 tables and 1 note.)