Abstract: A process for the enhanced oil recovery of underground mineral oil deposits, in which one or more substances which are scarcely water- and oil-soluble at deposit temperature but are well soluble or volatile in the hot flooding medium and whose melting point lies above the deposit temperature, are added to the flooding medium hot water and/or steam. They move with the hot flooding medium through the deposit and precipitate as a solid preferably at that part of the temperature front which is advancing fastest, thereby constricting the pores of the deposit temporarily and reversibly, until the solid is dissolved or evaporated again by repeated flow of the hot flooding medium, which has the overall effect of an areal and vertical equalization of the temperature front.