We present the results of pressure-dependent photoluminescence (PL) studies of single-crystalInxGa1−xN(0⩽x<0.15)films grown on top of thick GaN epitaxial layers by metalorganic chemical vapor deposition with sapphire as substrates. PL measurements were performed at 10 K as a function of applied hydrostatic pressure using the diamond-anvil-cell technique. The luminescence emissions from theInxGa1−xNepifilms were found to shift linearly toward higher energy with increasing pressure. By examining the pressure dependence of the PL spectra, the pressure coefficients for the emission structures associated with the direct band gap ofInxGa1−xNwere determined. The values of the pressure coefficients were found to be3.9×10−3 eV/kbarforIn0.08Ga0.92Nand3.5×10−3 eV/kbarforIn0.14Ga0.86N.©1997 American Institute of Physics.