Recent accelerated developments in the business environment have made customer knowledge to be a key competitive factor. Customer knowledge represents an important organizational asset that organizations would utilize and manage to gain competitive advantages. In addition to this, given the fact that service industry competition has increasingly been complicated, more attention has also been turned to customers and the concept of Customer Knowledge Management (CKM). As such, the main objective of this study was to investigate how telecommunications companies in Can Tho city managed their customer knowledge to achieve organizational performance and competitive advantage. Keywords: Knowledge, customer knowledge management, case study, telecommunication companies