Marketing has a strong role in creating products and services offered in the market in today's particularly dynamic and turbulent business environment marked by daily struggle to keep market positions and realise competitive advantages. Unlike external marketing, internal marketing is still insufficiently researched and used in Croatian companies. Internal marketing comprises marketing know-how, skills, tools, methods and techniques used on the internal market (within the company) with the objective of achieving synergistic effect of all employees in conformity with basic targets, the mission and strategies of the company. The focus of this paper is the research of characteristics of internal marketing of companies working in the Croatian market. The aim of the research was to determine, by means of a preliminary research, the implementation of principles and internal marketing concept in Croatia and its representation within Croatian companies. Previous works and experiences published in foreign publications indicate advantages of implementation of this concept within companies in addition to a great impact on creation of competitive advantages, particularly in terms of services, customer satisfaction and loyalty of both customers and companies' own employees.