Recently, customer knowledge management has been widely recognized as a determinant of business performance. However, knowledge of customers that the organization gathers is useless unless it is shared internally. Sharing of this knowledge among organizational members will greatly strengthen the competitiveness of the organization, which makes it possible to take advantage of the competitive dynamics in the business environment. Although the importance of knowledge sharing especially the one that is related to customers has long been recognized by the community of researchers, investigation in this area is very limited. Therefore, the present study was conducted to investigate the relationship between Customer Knowledge Management dimensions, which consist of knowledge for customers, knowledge about customers, knowledge from the customer and knowledge sharing among insurance companies in Malaysia. A total of 180 managers of insurance companies in Malaysia participated in the survey. The results show that the three knowledge dimensions are positively and significantly related to knowledge sharing. Moreover, the results indicate that the insurance companies have implemented knowledge sharing practices especially in securing and managing their customer data to ensure the currency, accuracy, uniqueness and completeness of the customer data. Finally, research and practical implications are discussed.