A statistical kinetic model for gradual degradation of semiconductor lasers and light‐emitting diodes under the influence of pressure is presented. Within the framework of this model, the rate coefficient for disordering atom jumps,K, and the operating lifetime of the device, &tgr;, are explicitly given in terms of temperature, pressure, material parameters, and free‐carrier concentration. We find that a compressive pressure reduces the effective activation energy of the rate process and therefore accelerates degradation in GaAs‐ and InP‐based devices.