Zinc sulfide (ZnS) thin films have been deposited on Si (100) substrate using ultrasonic spray pyrolysis. X-ray diffraction (XRD) analysis revealed that the films are (002) preferentially oriented with c-axis-oriented wurtzite structure. The crystallinity has been found to improve with film thickness in the 180-6000nm range. Film structure has been analyzed by XRD, scanning electron microscope, FTIR, and Raman spectroscopies, while the stoichiometry has been verified by energy-dispersive spectroscopy and particle-induced X-ray emission techniques. Electrical properties of the grown films were characterized by current-voltage and capacitance-voltage measurements where, the films show better conducting behavior at higher thickness.