Abstract: A heat exchanger comprises a pair of spaced fittings each having a first opening on one side thereof for communication with a fluid carrying conduit. The fittings are connected to one another by at least one pair of tubes extending from second sides of the fittings in fluid communication with the first openings. The tubes diverge away from one another as they extend from the fittings and may be provided with heat dissipating fins. The tubes are preferably semi-circular in cross-section and in one form of the heat exchanger the tube ends are received by round openings in the fitting. By this construction, the use of header tanks and their associated disadvantages is avoided and a heat exchanger is provided which can withstand high internal pressures and is readily manufactured in a cost effective manner.