The purpose of this thesis is to explore and analyse the necessity of cooperation between the logistics and marketing functions in modern business and to identify the key obstacles and opportunities to enhance this cooperation in order to make the company as successful and competitive as possible in the market. The aim of the study is to identify and explain the main challenges that stand in the way of cooperation between logistics and marketing, such as different goals and priorities, lack of communication, inconsistent reward systems and different success criteria. It also examines how changes in consumer habits, such as the increasing need for personalised and fast services, affect the need for more intensive integration and cooperation between these departments. The work highlights the importance of using common technologies and integrated information systems that allow for better demand forecasting, optimisation of inventory management and efficient return management. It further emphasises the importance of joint strategic planning as well as continuous training of staff in both departments. The recommendations for improving mutual relations include improving communication through regular meetings and a transparent exchange of information, by defining common objectives and key performance indicators (KPIs), and by forming teams to work on specific projects. The work also provides a theoretical framework and practical guidelines that may be useful for future research and application in real business environments in order to make companies as efficient and competitive as possible in the market.