Indium Sulfide thin films have been deposited on glass substrate using a simple and inexpensive technique viz., successive ionic layer adsorption and reaction (SILAR). The films are characterized using X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and optical absorption techniques. Samples are prepared by varying dipping and rinsing time, and those prepared at room temperature are found to be amorphous in nature. However, peaks corresponding to β-In2S3 are observed, on annealing at 400 °C. Grain size is found to increase with increase in the dipping times, either in the precursor solutions or in water. Band gap decreases considerably for samples annealed at 400 °C in vacuum. © 2006.