Modern companies must continuously develop their skills to meet the demands of the market. Independent development of these competencies (ex. through knowledge management and R&D) is insufficient and therefore companies seek new competences in their environment, among their suppliers, competitors, research institutions, universities. But still, customer is only a little appreciated source of knowledge. As far as institutional client is concerned, it often can give a company a broad knowledge along with his requirements for products or services, whereas the individual client is often ignored. Classical knowledge management systems and CRM acquire information about the client and possibly only the elementary knowledge from him, but without engaging potential customer directly in the process of creating new knowledge. The customer knowledge management (CKM) properly fills that gap. The main aim of CKM is to optimize the exchange of knowledge between the firm and its institutional and individual clients and use their creative potential. In the article CKM is defined as an activity of planning, organizing and controlling projects with regard to knowledge and innovation potential of a customer. The aim of this activity is gaining customer knowledge and its further developing by combining obtained knowledge with the company's one, and also jointly creating a new knowledge to improve the company's activities and development of innovative solutions (especially products and services). The article describes the differences between knowledge management, CRM and CKM, and characterizes the main processes on which CKM focuses. It also tells how to implement CKM and stresses that its worth of practical implementation, further development research.