Freedom of movement for workers is one of the four fundamental market freedoms. guarantees a person the right to work, i.e. to look for a job outside their home country. In such cases, it is very important for workers that their family members can legally enter and reside in the territory of another state, but also have the same rights as the local working population. In the context of the entry and stay of family members, the process of family reunification is discussed. This paper showed how family reunification is regulated by European directives. Depending on whether they are citizens of the Union or third countries, the legal basis also differs. It has been established that certain conditions must be met in order for family reunification to be approved. Otherwise, the right to family reunification may be restricted. For non-EU citizens, much stricter conditions apply. Furthermore, it has been established that the rights of family members, and the worker himself, should be the same as the rights of the local population, but there are certain exceptions when the rights can be limited. Croatian legislation also recognizes the institution of family reunification, which mostly refers to third-country nationals, i.e. those who are not EU citizens. Such citizens should submit an application for family reunification which is then analyzed and, if all conditions are met, approved. In Croatian law, a temporary stay of a family member can be granted for the purpose of family reunification, which means that such a person does not necessarily have to look for a job, work or study in the Republic of Croatia. This also simplifies the process of family reunification to some extent.