Abstract 
The influence of Fe3+ ions concentration upon gold extraction to thiourea solution by means of rotation disc electrode method was studied. Connection between Fe3+ ions concentration in solution and thiourea concentration was also investigated. High content of Fe3+ in solution means increase of oxidation power of surroundings and it results in thiourea destruction and besides its loss for leaching it means decrease of gold extraction in solution. It is possible to state that redox potential in solution around 200 mV means maximum efficiency of gold extraction into solution. It has to be said that amount of oxidative reagent for the gold leaching must be precisely determined for every leached material. The excess of oxidation media means the destruction of thiourea and that means increase of leaching cost.