This study examines whether incentives affect public employees’ intention to share knowledge. Tested incentives satisfy needs for either achievement or appreciation. Both treatments were tested on implicit as well as explicit knowledge sharing. A 2 × 3 factorial survey experiment was designed to observe within-person and between-person effects. Data were collected from public employees in the core administration and healthcare sector (n = 623) in 2018. The analysis indicates that both treatments positively affect knowledge-sharing intention if it is explicit knowledge that ought to be shared. However, no effects of either treatment can be found in either type of knowledge sharing. No negative effect of the tested incentives on knowledge sharing was observed. Hence, incentives might not harm knowledge sharing but also do not pay off in organizational practice. In contrast to these motivation-enhancing human resource practices, ability and opportunity-enhancing practices should be tested to foster knowledge sharing.