INTRODUCTION: The interest in continuing education (CE) for pharmacists has increased because of patient safety issues, advancing science and the quick changes in the profession. Therefore, contemporary pharmaceutical care requires an effective and sustainable system for pharmacists to maintain and improve competencies. Although motivation plays an important role both as a facilitator (desire to learn) and a barrier (lack of motivation), there is little investigated about this specific factor. The aim of the study was to explore what factors influence pharmacists' participation in CE with a focus on motivation. METHODS: The theoretical framework was self-determination theory (SDT), which describes autonomous motivation (AM) representing motivation from an internal locus of causality, controlled motivation (CM) originating from an external locus of causality, and relative autonomous motivation (RAM) that measures the AM in an individual after correcting for the CM. The relationship between pharmacists' characteristics, especially their motivation (AM, CM and RAM) in CE, and their participation in CE activities was explored using the AMS-questionnaire and the Dutch online portfolio system. RESULTS: RAM was positively correlated with CE participation of pharmacists and explained 7.8% of the variance. The correlations between the independent variables AM and CM and CE hours were negative (-0.301 and -0.476, respectively). Other factors influencing CE participation were pharmacy school (6.8%), traineeship (10.9%), and work experience (7.8%). Pharmacists participated for 27.0 hours on average in CE during 11 months and preferred face-to-face-learning (85.5%) above e-learning (13.8%). DISCUSSION: Our findings show a positive relationship between RAM and CE participation. The current CE system is probably not conducive to stimulation of AM. Further research is needed to understand the factors that stimulate pharmacists' motivation and participation in CE.