The legal basis of regional organizations usually comprises three sources namely: constituent international treaty, other treaties adopted within the regional organizations and eventually the rules of their internal legal order. Speaking broadly, the contribution of international judicial bodies to international law may consist in the "gap-filling" of international treaties, in the adoption of a binding interpretation of the treaty and stabilization of the recognized meaning of the treaty. One of the consequences of the judicialization of international law in the late 20th century is a growing number of advisory jurisdictions within judicial bodies of regional organizations from different geographic areas. The analysis clearly confirms the uneven level and complexity of regional human rights systems in different parts of world. Their particularities result from a set of various factors having historical, religious, ethnic and other natures.