The Metabolite and European pharmacopoeia impurity G of Risperidone, chemically known as 3-[2-[4-(4-fluoro-2- hydroxybenzoyl)piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido -[1,2-a]pyrimidin-4-one (2, Risperidone hydroxy keto analogue), preparation and its structural confirmation by spectral analysis data have been described.