Threshold current density is studied theoretically for InGaAsP multiple quantum well lasers by including the Auger recombination process. All the possible transitions between quantized subbands of two‐dimensional carriers are taken into account in evaluating radiative and Auger processes. The Auger recombination current depends strongly on the quantum well structure, resulting in the necessity for an elaborate structure design. A design procedure is elucidated for the structure which gives the lowest threshold current density for InGaAsP multiple quantum well lasers.