We report the diffuse light-scattering properties of nanocracked and porous molybdenum trioxide (MoO3) films deposited on indium tin oxide (ITO) coated glass as a transparent conductive oxide (TCO), caused by the enhanced light diffraction due to high surface roughness as well as narrow slit-like structures. By utilizing the electrodeposition and thermal annealing processes, the hydrous and amorphous molybdenum oxide films were changed into crystallized MoO3 films with self-formed nanocracks and rough surface. From the theoretical analysis of the light behavior passing through the morphology of MoO3 films, a considerable diffuse light scattering was predicted. In order to optimize the light-scattering property, the structural and optical characteristics of MoO3 films on ITO/glass at different applied voltages were investigated. For a proper applied voltage of 2 V, widely distributed nanocracks and rough surface were observed, leading to the enhanced diffuse transmittance of 54% at λ ∼ 410 nm. Additionally, the fabricated MoO3 films on ITO/glass exhibited a more hydrophilic surface.