Given that integration in various spheres of international relations became a priority trend, the joint effort of the international community in combating crime can be considered certainly one of the priorities of the international cooperation. In the process of cooperation the states resolves important issues such as harmonizing the qualifications of offenses endangering several states, coordinate the measures for their prevention and repression, achieving jurisdiction over offenders, legal assistance in criminal matters. Among the various forms of the international cooperation, the one that has evolved the most in recent years is the international legal assistance - an effective form of international cooperation by a state to another state seeking or offering help in obtaining evidence in criminal cases. In this article the author aims to elucidate and analyze, in terms of international regulations and doctrinal views, the notion, the forms and the peculiarities of the international legal assistance in criminal matters institution.