GaAsP red‐light‐emitting diodes containing 40% phosphorus were stressed uniaxially in the [100] direction at 77 K. The spectral emission peak was observed to shift to higher energies at the rate of 2.1 ± 0.2 meV/kbar. From the stress dependence of the recombination current, the band‐gap stress coefficient is 3.6 ± 0.3 meV/kbar. By using the fact that radiative recombination takes place via a band‐acceptor (Zn) process, it is concluded that the acceptor level moves away from the valence band at the rate of 1.5 ± 0.4 meV/kbar. The intensity‐voltage characteristic is consistent with the interpretation that the effect of the uniaxial stress is to deionize the acceptor level, which causes a smaller decrease of intensity with stress than would be expected from band‐gap deformation alone. The effect of uniaxial stress on the indirect‐direct conduction‐band transition is discussed.