A flat tube for a heat exchanger may include a longitudinal-end inlet for letting a fluid into the flat tube, and a longitudinal-end outlet spaced apart from the inlet in a longitudinal direction for letting the fluid out from the flat tube. The flat tube may also include flow elements around at least a portion of which the fluid may be flowable around the flow elements in such a manner that the fluid may have a flow direction component perpendicular to the longitudinal direction. The outlet and the inlet each may be delimited on a partial cross-sectional area of the flat tube and arranged diagonally opposite one another.