This study develops a photosynthetic microalgae microbial fuel cell (PMMFC) engaged Chlorella vulgaris microalgae to investigate effect of light intensities and illumination regimes on simultaneous production of bioelectricity, biomass and wastewater treatment. The performance of the system under different light intensity (3500, 5000, 7000 and 10,000 lx) and light/dark regimes (24/00, 12/12, 16/8 h) was investigated. The optimum light intensity and light/dark regimes for achieving maximum yield of PMMFC were obtained. The maximum power density of 126mWm(-3), the coulombic efficiency of 78% and COD removal of 5.47% were achieved. The maximum biomass concentration of 4 g l(-1) (or biomass yield of 0.44 g l(-1) day(-1)) was obtained in continuous light intensity of 10,000 lx. The comparison of the PMMFC performance with air-cathode and abiotic-cathode MFCs shows that the maximum power density of air- cathode MFC was only 13% higher than PMMFC.