The ignition delays of freely-falling droplets of 300-400 mu m size in a high temperature oxidizing environment were experimentally determined as functions of the environment parameters and droplet composition. Results show that the ignition delay decreases with increasing system temperature, oxygen concentration and pressure, that for pure fuels within the same homologous series the ignition delay is longer for the heavier fuels, that the addition of a small amount of a more volatile fuel to a less volatile fuel of similar chemical reactivity can significantly reduce the ignition delay, and that the chemical sensitivity of the ignition delay is reduced with increasing reactivity of the environment. The importance of allowing for and distinguishing the influences of chemical versus physical delays in assessing the overall ignition delay is emphasized.