The invention relates to a heat exchanger, especially a heat exchanger for motor vehicles, comprising a bank of tubes through which a gaseous medium flows and around which a liquid coolant flows. The ends of said tubes are received in tube plates and are connected to the same in a material fit. The inventive heat exchanger also comprises a housing jacket which surrounds the bank of tubes and is connected, at the end thereof, to the tube plates. A coolant flows through said housing jacket. The tubes, tube plates and housing jacket are produced from a heat-resistant and corrosion-resistant metallic alloy. According to the invention, the housing jacket comprises at least one surrounding expansion flange.