It is becoming clearer that the Republic of Croatia approaching the European monetary union in the near future euro will supstitute the Croatian kuna. Before the implementation of euro a contry must first fulfill the Maastricht criteria also known as criteria of convergence. All systems have some advantages and disadvantages, and so does joining the European monetary union. The examples of Slovenia and Slovakia show that those advantages and disadvantages present themself diferently after joining the union, depending on the conditions in the contry. The question is how will the advantages and disatvantages effect Croatian companys and will joining the European monetary union bring more benefit or cost. The company will after accession to the European monetary union expirience advantages in lower transaction costs in international trade, elimination of currency risk that can cause large costs by currency fluctuations when assets and obligations are tied to euro. By larger transperency in prices the company will have an easier task in selecting suppliers. Of the disadvantages of joining the European monetary union, the compay can expect to expirience an raise in costs for adjusting its computer systems and gear, as well as training its staff for using the systems and gears. These disatvantagese are one-time costs and can be minimalised by adequate preparation. The real effects of joining can be properly analized several years after European monetary union membership, but on the basis of analizing and examination on available information of the company, it is concluded that the company will have more benefit then cost from joining the European monetary union.