The fluorescence lifetime of toluene in the gas phase upon excitation at 248 nm was studied as a function of temp. (296-625 K) via time-correlated single-photon counting (TCSPC) in N bath gas at 1 bar total pressure. The fluorescence decay can be represented by a bi-exponential function. Lifetimes are decreasing with increasing temp., with the long lifetime component ranging from 45 to 2 ns and the short component from 2 to 0.4 ns in the studied temp. range. Results suggest high repetition-rate laser excitation of tracers like toluene in combination with TCSPC as a novel tracer-concn.-independent method for detg. gas-phase temps.