We present an experimental and theoretical study of the role of band filling effects in the hydrostatic pressure dependence of photoluminescence PL from InN. The PL peak pressure coefficient dE PL / dp is shown to decrease from 27.3± 1.1 meV/ GPa to 20.8± 0.8 meV/ GPa when the electron concentration increases from 3.6 10 17 cm −3 to 1.1 10 19 cm −3 . We argue that this decrease is caused by the pressure sensitivity of the Fermi level in InN, which induces a lowering of dE PL / dp with respect to the band gap pressure coefficient dE G / dp. dE PL / dp is shown to depend on the electron concentration in accordance with predictions based on ab initio calculations, taking into account the influence of conduction-band nonparabolicity.