The theme of this diploma thesis is Customer Relationship Management on the business spending markets. Customer relationship management is the strongest and most effective approach to maintaining and building relationships with customers. Customer relationship management is not just pure business, but it is creating relationships with customers. The development of these types of relationships drives business to new levels of success. CRM enables organizations to building relationships with customers to identify users, and in particular their wishes and needs, and how to serve them in the best way. Users are for companies one of the important factors in the market, but just customer relationship management enables organizations to focus on relationships with certain people, whether they are customers, clients, suppliers or colleagues. Some of the benefits system Customer Relationship Management gives, are the transparency of information and user data, the importance of understanding the user, completed data about users. But there are also disadvantages such as large financial investment, resistance to change, while in practice most users of CRM systems as the biggest disadvantage is time. The system requires a good education and training, and with the understanding of the purpose of using a CRM system, greatly simplifies operations and customer relations. The aim of this diploma work is to point out the need of managing relationships with customers in the business market, display system through the implementation and operation, customer satisfaction and employee and ultimately the results that led to the implementation of the system in the company. The company has been taken as an example for the analyze is the company Uponor, an international supplier of plastic pipes and a market leader in its segment.