AbstractThe views of researchers on the causes of mud volcanism have evolved over time. At the early stages, mud volcanoes were considered to be similar to ordinary volcanoes. Later, they began to be associated with processes in sedimentary basins, although there are still attempts to link mud volcanism with magmatic manifestations and replenishment with juvenile components. Finds of mercury, native gold, silver, sulfur, copper, iron, and accessory minerals in the products of mud volcanoes in recent years have led a number of researchers to presume the existence of deep through flows of hydrocarbons from the mantle and to consider mud volcanoes as a kind of degassing pipe. The results of our analysis of the trace-element compositions of mud volcano sediments in the different regions of the world (Kerch Peninsula, Northwest Caucasus, Sakhalin, Dzhungar Basin, Andaman Islands, Gulf of Cadiz, Eastern Mediterranean, and East Java) confirm the idea that no traces of the impact made by mantle/juvenile components are observed in those regions, as in the composition of mud volcano fluids (water, methane, carbon dioxide, and helium).