This paper provides an overview of different models of international police cooperation through Europol, Interpol and Schengen Information System. Current state in Croatia is presented and analysis of gathered statistical data has been conducted with special review on how Croatia's entering EU affected operational information exchange and the number of cases of criminal investigation in international police cooperation. In the chapter on Europol total number of exchanged messages, type of messages and total number of cases originated from incoming messages in a designated year have been analized. In the chapter on Interpol total number of issued and cancelled international notices has been analized as well as number of cases of operational data exchange on the foreign request, on the request of Croatian authorities and total number of executed extraditions and transfers of convicts has been presented. In the chapter on SIRENE and SIS cases of European arrest warrant received in Croatia after 1st of July 2013 have been analized, as well as number of European arrest warrants issued by the competent Croatian judicial authorities. Based on the number of arrested persons in 2014 in Croatia, the duration of procedures has been analized from the moment of arrest until the surrender in the cases of extradition and cases of EAW surrender. This paper provides comparison of similarities and dissimilarities of above mentioned models and finishes in consideration of new challenges which are to be expected upon gaining full membership in the EU.