Nowadays companies’ competition for acquiring new customers and retaining the existing ones has sharpened, so it became more important in case of a company to treat their customers adequately, to create relationship with them based on trust, and to keep their needs in priority. Therefore, the importance of the stored and processed information about the customers got great emphasis to meet their demands, and CRM systems provide great solutions for that. Usually when someone thinks about CRM systems, it can be considered as difficult softwares can be utilized only by larger enterprises’. Although it is well-known that these systems mainly belong to the multinational companies’ business culture for now, but it does not mean that small and medium-sized enterprises should not need them, as CRM systems are not just additional software solutions for companies, but indispensable tools of effective customer relationships. My research aim is to analyse micro, small and medium-sized enterprises’ customer relationships, and their methods to support these relations, marketing and sales activities. Furthermore, I examine if professional CRM systems could be generally relevant to SMEs’ business culture. I also try to find out, what factors the CRM system usage depends on, and how the CRM adoption rates can be improved.