Artificial intelligence is a technology that allows computers and machines to simulate human intelligence when solving complex problems which has created significant value for many industries over the years, including the field of marketing. In the past few years, artificial intelligence has become crucial in the business of marketers, enabling them to automate routine tasks, personalize the user experience, perform predictive analytics and many other aspects of business that previously required significantly more time and resources. The paper investigates the use of artificial intelligence (AI) among marketing agencies in the Republic of Croatia with the aim of analyzing the level of acceptance of the mentioned technology in business, understanding the impact of AI technology on the improvement of marketing activities carried out by marketing agencies and identifying the advantages and challenges they face during its implementation. The research results show that 89,9 % of marketing agencies in the Republic of Croatia use UI in their business, where it is most often used in content generation and editing, task automation and market research, while the most popular UI tools include ChatGPT, Canva AI and Grammarly. Further development of artificial intelligence technology and their implementation in business processes will further improve the efficiency of marketing agencies and help them provide more personalized services. The importance of the ethical use of artificial intelligence in business which is necessary for building trust with clients was emphasized and recommendations were proposed so that marketing agencies in the Republic of Croatia could fully utilize the opportunities that artificial intelligence provides, including continuous employee education and monitoring of new trends.