Final paper Direct marketing in Croatian telecommunication companies consists of five chapters. The introduction seeks to describe all the problems of the telecommunication industry in relation to direct marketing, which is described in detail in the second chapter through subjects like: relationship between direct and classical marketing, personal sales and telemarketing, basic characteristics of direct marketing, it´s objectives, functions and strategies. The third chapter provides an overview – history of development of telecommunications industry in Croatia and the world, with an emphasis on the period after the 1990s. There is a timeline of events, from the discovery of telephone to the introduction of the Internet and the appearance of the first mobile operators. The fourth chapter is focused on the analysis of the telecommunications industry market (From market shares and the distribution of users to marketing methods that operators use) using desk research, and is mainly based on secondary data from relevant sources. Emphasis is thereby placed on the analysis of marketing campaigns and various loyalty programs combined with CRM (customer relationship management) – business strategy used by some operators in Croatia to increase customer satisfaction and retention. Call center is thereby one of the basic marketing strategies telecommunication operators use and is based on the organizational structure and databases of each operator. The paper is concluded by summarizing all the information gathered in the previous chapters and provides evaluations and projections of the future in Croatian telecommunications. The aim of this study was to analyze the telecommunication companies and customer loyalty in Croatia. One of the secondary objectives was to determine whether it is worthwhile to invest more in retaining existing customers or acquiring new ones. The results showed that both components are equally important, but to achieve significant growth vertical or horizontal integration of other companies through acquisition or establishment of new sister companies is required.