Knowledge is a valuable resource that can lead to improved organizational performance and competitive advantage. Knowledge resides in individuals and knowledge sharing is a process that creates organizational knowledge resources by disseminating the knowledge of individuals. However, knowledge sharing is dependent on the willingness of individuals in the organization to share. Many organizations have created reward structures to encourage employees to contribute to knowledge repositories or share their knowledge through online forums. Many reward schemes depend on monetary rewards such as payments or promotions. However, prior research demonstrates that these tangible rewards may not always encourage sharing with some reporting negative effects for tangible rewards. The literature on incentives and motivation identifies other types of rewards - verbal rewards, reputation and reciprocity. This study investigates the impact of different types of rewards on attitude towards knowledge sharing through a survey of knowledge workers. The results confirm the importance of verbal rewards and extrinsic rewards based on social capital. However, monetary rewards did not have a significant effect. The paper concludes with a discussion of the implications for practice and future research.