The Republic of Croatia, 1 July 2013 as a full member of the European Union, is obliged to implement Union's legal acts into national legislation. The Union is based on four basic freedoms: free movement of goods, capital, services and workers. I order for Member Sates to respect all market freedoms, it was necessary to determine the scope of freedom of movement for workers. Free movement of workers achieves the basic purpose and objective of the European Union as well as strengthening the single European market in order to compete with major world powers. Free mobility of workers is one of the fundamental freedoms on which the European is based. It is defined by the Art. 45 of the Treaty on the Functioning of the European Union and entails the abolition of any discrimination based on nationality in relationship to employment between workers of the Member States. Art. 45, par. 4 of the Treaty on the Functioning of the European Union stipulates that the provisions of this Article shall not apply to the employment in public services. Since the Republic of Croatia is still a young member state, we have analyzed the migration of Croatian workers in the European Union, as well as the transition period for Croatian workers. Through case law, we have analyzed what the free movement of workers has actually achieved in the Member States, and we can see how Court of Justice of the European Union affect the further development of free movement of workers.