Leadership can play an important role in knowledge hiding. This study investigated the unexplored impact of altruistic leadership (AL) on knowledge hiding by assessing the mediating role of team learning (TL) and knowledge culture (KC) in this relationship. Structural equation modeling was used to test 14 hypotheses based on primary data from 368 surveyed Slovakian companies representing diverse enterprises. Data were gathered from various companies spanning a range of industries, including manufacturing, education, wholesale and retail, construction, and information technology. Of these, 164 were from micro-enterprises, 114 were from small enterprises, 67 were from medium-sized enterprises, and 23 were from large enterprises. This article reveals how AL can mitigate the negative effects of knowledge hiding by supporting TL and cultivating a KC. These findings indicate that leaders who exhibit altruistic behavior positively influence TL, enhancing KC and reducing instances of knowledge hiding. The primary data tested in our model confirm that selfless leadership reduces knowledge hiding by encouraging TL and KC. This suggests that, when selecting team leaders, their level of altruism should be considered. The roles of TL and KC in promoting knowledge sharing within organizations and emphasizing the importance of team effectiveness and mutual communication are crucial. This study contributes to the existing literature by examining the direct impact of AL on knowledge-hiding behavior, demonstrating how AL promotes TL and a knowledge-sharing culture, thereby eliminating knowledge hiding, including the practical implications. Future qualitative studies and research extending to other locations could help deepen our understanding of these relationships and incorporate additional concepts and factors.