Performance of 1″ × 1″ LaBr₃ (5% Ce) scintillator coupled to Hamamatsu R2083 PM Tube has been investigated for the first time. Energy response and timing characteristics of the present assembly have been studied at different operating conditions for its application in fast timing spectroscopy. An energy resolution of 3.38 ± 0.03% at 662 keV γ-energy was obtained in the present work at a bias voltage of − 2800 V and a linear response could be observed up to a bias voltage of − 2500 V. Time resolution of a single LaBr₃:Ce crystal was found to be 174 ± 2 ps and 121 ± 3 ps for 511–511 and 1173–1332 cascades respectively. Effect of applied bias voltage on the time resolution of the set up was studied and a steady improvement with increasing bias voltage was observed. Present results were compared with the previous results obtained with similar fast PM tubes and importance as well as implications of the present measurement were also discussed.