Purpose – This paper aims to investigate the joint influence of employees' career motivation and their self-construal on their engagement in three informal workplace learning activities: keeping up-to-date, asking for feedback from supervisors and knowledge sharing. Design/methodology/approach – Data were collected through an online questionnaire from 323 employees from four Dutch Vocational Education and Training (VET) schools. Regression analyses were used to test the hypothesis. Findings – Career motivation is positively related to all three informal learning activities. Employees' individual self-construal strengthens the relationship between career motivation and engagement in the learning activity of keeping up-to-date, while employees' collective self-construal strengthens the relationship between career motivation and engagement in the learning activity of knowledge sharing. Contrary to expectations, employees' relational self-construal does not strengthen the relationship between career motivation and engagement in the learning activity of feedback asking from supervisors. Research limitations/implications – The use of cross-sectional data collection made this study vulnerable to common method bias. Future studies should consider using a longitudinal research approach to overcome this limitation. Practical implications – The findings suggest that both the motivational issue of “what do you want” and the self-identity issue of “who you are” are important for employee informal workplace learning. For human resource (HR) professionals this suggests that they should stimulate employees' career motivation, while for employees this suggests that they should engage in informal learning activities in keeping with their own style. Originality/value – This is one of the first studies to provide empirical support for the joint influence of career motivation and self-construal on employees' informal workplace learning.