Physical properties of a nanocrystalline thin film is greatly influenced by its morphological and structural evolution. We try to understand the transition of SnO 2 thin films from amorphous to nanocrystalline structure with XRD, IR, SEM, AFM and surface profiler studies. A 2D layer like structure resulting from quantum confinement is found for the films prepared at 400°C. We observed a new IR band at 530cm −1 that was theoretically predicted and report it for the first time. A correlation of population of defects in SnO 2 films with change in lattice parameters and FWHM of IR bands are reported. The electric and optical properties of the films have been discussed.