Ultrasonic spray coating is reported as a deposition method for thin silicon films using a mixture of silicon nanoparticles and organosilicon compounds. The as-deposited films were treated by flash lamp annealing (FLA) using xenon light in order to obtain polycrystalline silicon. The nanoparticles were characterized by diffuse reflection infrared Fourier transform spectroscopy, transmission electron microscopy, and powder X-ray diffraction prior to deposition and film formation. The effect of FLA on the morphology of silicon films obtained from these silicon nanoparticles is investigated. Thin polycrystalline films up to 4 A mu m with a silicon content up to 95 % were prepared by combining the use of ultrasonic spray coating and FLA.