Laser-induced incandescence (LII) is investigated in laminar premixed flat ethylene/air flames at pressures up to 5 bar in a recently constructed high-pressure burner. Time-resolved LII signals were compared with a numerical model considering the influence of pressure on the LII signal decay. Peak particle temperatures after laser heat up were measured by the detection of the LII signal at two wavelengths. Laser-induced emission spectra enabled to check for interfering signals. Gas-phase temperatures were required to compare the LII signal decay with the model and were measured using multi-line NO-LIF thermometry.