Abstract: A tubular heat exchanger, which may be used as an automobile radiator or the like, comprises tubes for transporting a liquid heat transfer medium between two collecting chambers, and lamellar baffles, supported by the tubes in substantially perpendicular relationship thereto, for intercepting a gaseous heat transfer medium flowing past the tubes. The tubes are disposed substantially equidistant one from another such that, when viewed in cross section, their centers are arranged in series along a first line which extends uniformly back and forth with respect to a substantially straight second line. Each section of the first line, which extends from one side to the other of the second line, passes through at least three tubes.