A process for the preparation of pure Regadenoson comprising； a. dissolving impure Regadenoson in a mixture of at least one solvent selected form the group consisting of amides, sulphoxide and at least one solvent selected from the group consisting of alcohol； b. treating the solution obtained in step(a) with one anti-solvent selected from the group comprising of nitriles, alcohols or mixture thereof； c. filtering the solid obtained in step (b) to attain pure Regadenoson； d. dissolving Regadenoson in at least one solvent selected from the group consisting of amides, sulphoxide or mixture thereof； e. treating the solution obtained in step (d) with co-solvent to get crystalline form of Regadenoson monohydrate.
