La2CoO4 is synthesized by a fast and simple microwave method using lanthanum nitrate and cobalt nitrate as starting reagents. La2CoO4 is synthesized using microwave heating for 6 mins. without calcination step. The synthesized product is characterized by X-Ray powder diffraction (XRD). The photocatalytic behaviour of La2CoO4 was studied spectrophotometrically through bleaching of azure-B and yellowish orange dyes. The effect of variation of different parameters i.e. pH, amount of La2CoO4, concentration of dye and light intensity was studied on the rate of photocatalytic degradation. A tentative mechanism for photocatalytic degradation of dyes has been proposed.