SnO2 nanoparticles (NPs) were synthesized through the ultrasound-assisted method. Structural and morphological properties of the prepared sample were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The result of XRD analysis showed that SnO2 NPs has tetragonal structure. The mean nanocrystallite size of the prepared SnO2 nanostructure has been estimated less than 30 nm. The formation of nearly spherical SnO2 NPs is depicted by SEM images. Brunauer-Emmet-Teller (BET) and Energy Dispersive X-ray (EDX) analysis was used to measure of surface area and investigation of purity of the prepared sample, respectively. UV-visible spectroscopy was utilized to evaluate the optical property and photocatalytic activity of the as-prepared sample. Blue-shifting in band gap energy is founded from the UV-the visible analysis. The results of photocatalytic activity investigation of the sonochemically synthesized SnO2 NPs revealed that such material can be used as good photocatalyst for degradation of methylene blue (MB). The overall investigation of the results obtained by photocatalytic activity of the prepared SnO2 NPs shows this nanostructure has highly photocatalytic activity under UV-Visible irradiation.