The effect of turbulence on flame kernel growth in lean propane-air mixtures has been studied in a flow reactor at atmospheric pressure and 300 K using laser ignition. The flame kernel growth rate was measured using laser shadowgraphy. Measurements were made under two different turbulent flow conditions, with two different ignition energies and over a range of fuel to air ratios. The effects of these parameters on flame kernel growth through changes in the mass burning rate and the expansion velocity are discussed. A comparison of the effect of turbulence on ignition probability and flame kernel growth rate variation is also presented.