This study used microwave-assisted hydrothermal (MHT) methodology to successfully synthesize highly crystalline perovskite-type NaTaO3. Calcination at 800, 850 and 900 degrees C was performed to evaluate MHT's effects on NaTaO3's crystallinity, optical properties, morphology and photocatalytic performance. Grain growth-induced irregular agglomerations reduced the surface area of the calcined samples, negatively affecting photocatalytic performance. Ta-O bond of sodium tantalum was detected in all samples by FTIR spectra analysis, proving the success of MHT. Based on the results of photocatalytic experiment using methyl-blue aqueous solution under both UV and visible (white-light LED) light irradiation, the non-calcined NaTaO3 performed better than the calcined ones. Thus, calcination does not always guarantee a better photocatalytic performance of NaTaO3. The performance of the non-calcined NaTaO3 exposed to five hours of visible light irradiation (60%) was less positive than that exposed to UV irradiation (90%). This photocatalyst holds promise for the treatment of wastewater in the future. (C) 2017 Elsevier Ltd. All rights reserved.