We synthesized four different photocatalyst systems viz. Zn2TiO4, Zn2Ti1-xFexO4, Zn2Ti1-xCrxO4 (0 ¡Â x < 0.8) and Zn2Ti0.9CryFe[0.1]-yO4 (0.022TiO4 was converted to visible light active material by controlled doping/co-doping of Cr and Fe metal-ions at Ti substitutional site. We investigated their structural, optical and photocatalytic water decomposition property. The co-doping induces strong absorption bands in visible region (at ¥ë~ 480 nm and ¥ë~ 620 nm) in the host band gap. The optimum system of Zn2Ti0.9Cr0.05Fe0.05O4 yielded maximum H2 generation. In contrast to the visible light inactivity of Fe and Cr doped Zn2TiO4, the H2 production under visible light irradiation from co-doped samples, increased till the optimum ¡®y¡¯ value. Consequently, there exists an optimized co-dopant concentration for efficient photocatalytic hydrogen production under visible light (¥ë ¡Ã 420 nm).