Diagnosis of primary & secondary brain tumors on imaging procedures alone is still a challenging problem. Also the radilogic assessment of suspicious brain lesions after sterotactic radiotherapy of brain tumors is difficult. Proton magnetic resonance spectroscopy( H1 MRS ) gives completely different information related to cell membrane proliferation, energy metabolism & necrotic transformation of brain or tumor tissues. This study was done to evaluate the clinical utility of H1 MRS added to MRI for the differentiation of intracranial neoplastic mass lesion.