Bi2Sn2O7 nanoparticles were successfully synthesized via a fast microwave-assisted method and high temperature treatment. The obtained nanoparticles were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), UV-Vis diffuse reectance spectroscopy (DRS), photoluminescence spectroscopy (PL), total organic carbon (TOC) measurement and Raman spectroscopy. We found that there is an optimal thermal treatment temperature for Bi2Sn2O7 for the highest photocatalytic activity in the decomposition of rhodamine B (RhB) under visible light irradiation. We observed an improvement in activity when the thermal treatment temperature increases from room temperature to 500 degrees C, but the activity decreases when the sintering temperature is increased further. The reason behind the enhanced photocatalytic efficiency is a better separation of the charge carriers which is competitive with the specific surface area, crystallinity and crystal size.