Using quantum well laser devices with a window in thep‐type contact, we have measured the relative change of spontaneous emission intensity at threshold with temperature for 58‐A˚‐wide GaAs wells. Over the range 250–340 K the data are in good agreement with the linear relation obtained from a gain‐current calculation which includes transition broadening. This linear behavior contrasts with the stronger temperature dependence of the total measured threshold current of the same devices which includes nonradiative barrier recombination processes.