The measurements of the photoluminescence (PL) spectra have been performed on GaAs, GaMnAs, GaAs:Be, and GaMnAs:Be samples to study the effect of Be codoping on the PL spectra of GaMnAs layers grown via low temperature molecular beam epitaxy. Based on the temperature dependence of the exciton-related transitions energy, it was shown that doping GaAs with Mn and Be leads to modification of the temperature dependence of the band gap. It was shown that although Be itself weakly affected the PL spectra of GaAs, codoping with Be significantly modified the PL spectra of GaMnAs. (C) 2010 Elsevier B.V. All rights reserved.