This study examines and theorizes the effects of task challenge on skill utilization, affective wellbeing and intrapreneurial behaviour among civil servants through a real-life challenging assignment, which was part of a unique Dutch and Flemish bottom-up organized event called ‘Train Your Colleague’. Results of a short-term longitudinal study indicate that, as expected, task challenge is positively related to skill utilization and intrapreneurial behaviour but, unexpectedly, not to affective wellbeing. These results suggest that challenging assignments may be important tools to enhance employees’ skill utilization and intrapreneurial behaviour at the workplace. Implications for theory and practice are discussed.