Contingency theory is based on the effectiveness and efficiency of a certain company and is achieved only when an excellent adaptation is ensured among the structural organization of a company and its environmental conditions. The integrative aspect of an organizations operations is therefore an important aspect of functioning of each supply chain member. Consequently, each member has to be aware that external integration has several advantages, mainly reflected in increased company performance. Different members involved in the tourism supply chain are heavily reliant on each other and if one of them fails to deliver a service, it has an effect on the whole chain. Because of that they have to develop integrated relations between them and therefore assure the best possible performance of their supply chain. A significant role in the performance of the tourism supply chain is played by travel agencies. This study analyses the level of external integration between travel agencies, transport providers (water, air, rail and bus carriers), accommodation, restaurants and insurance companies. The analysis was carried out by using Structural equation modelling (SEM) to determine the levels of external integration between travel agencies and other members of the tourism supply chain. The SEM analysis was also used to identify existing behavioural relations between all observed members of the tourism supply chain.