The invention relates to a heat exchanger, particularly for a motor vehicle, comprising at least one duct (24-29) through which a fluid flows and of which at least some section have a curved shape. Preferably, said heat exchanger comprises several ducts through which a fluid flows and of which at least some sections have a curved shape. In order to increase the heat exchanging capacity, the duct (24-29) of which at least some sections have a curved shape is provided inside a profiled extruded element.