The cerium concentration and temperature dependence of the spectral distribution, quantum yield, and lifetime of the Ce3+ photoluminescence has been investigated in powders having the composition Sr1-2xCexNaxGa2S4 (x less than or equal to 0.5). With increasing cerium concentration the emission shows a strong shift to longer wavelengths caused mainly by changes in the ligand field. Despite a relatively small Stokes shift (2000 cm(-1)), the emission shows a low concentration quenching up to x = 0.10. Because of the size differences between the Ce3+, Na+, and Sr2+ ions, cerium ions possess various environments. Energy migration to defects is impeded by the transfer df the excitation energy to the ions having the lowest emitting states, whose emission exhibits reduced overlap with the absorption of other ions. As a result of the small Stokes shift, at low Ce concentration the luminescence is not affected by the thermal quenching up to 500 K. The low concentration quenching and the high thermal stability are favorable characteristics for use of this phosphor in electroluminescence and high current density CL screens.