We have investigated the time and energy resolution (TTiming, ∆E/E) of four different scintillator materials BaF2, BC-418, LYSO and CeBr3 at a gamma energy of 511  keV in views of their possible usage for time, energy and position resolution for positron annihilation experiments. The shape of each scintillator was a cylinder with a diameter of 25  mm and a height of 10  mm readout by a Photonis XP2020/URQ photomultiplier tube. The best single time resolution was determined for each photomultiplier–scintillator setup in a three step optimization process. The optimized single time resolutions (FWHM) for BaF2, BC-418, LYSO and CeBr3 were 119  ps, 117  ps, 269  ps and 127  ps, respectively. We measured the energy resolution of the photomultiplier–scintillator setups which show a photopeak in the energy spectrum. The energy resolutions ∆E/E of BaF2, LYSO and CeBr3 were 9.8