The photocatalytic inactivation of Escherichia coli was studied with combustion synthesized TiO 2 photocatalysts in the presence of visible light. A series of 400W lamps irradiating in the visible region of the solar spectrum was used. The effect of various parameters, such as catalyst loading, light intensity, presence of inorganic ions, addition of hydrogen peroxide and pH, on the photocatalytic inactivation of E. coli was investigated. Photolysis alone had a small effect on inactivation while the dark experiment resulted in no inactivation and Ag/TiO 2 showed the maximum inactivation. At a catalyst loading of 0.25g/L, all the combustion synthesized catalysts showed better inactivation of E. coli compared to commercial Degussa P-25 (DP-25) TiO 2 catalyst. An improved inactivation was observed with increasing lamp intensity and addition of H 2O 2. A negative effect on inactivation was observed by addition of inorganic ions such as HCO 3 -, SO 4 2-, Cl -, NO 3 -, Na +, K +, and Ca 2+. The photocatalytic inactivation of E. coli remained unaltered at different pH of the solution. The inactivation of E. coli was modeled with power law kinetics and was observed to follow first order kinetics. © 2012 Elsevier B.V..