The amino acid analogue 3-nitrotyrosine (3-NT) is formed in neural cells as a result of the intense stimulation of NMDA glutamate receptors. 3-NT is involved in the pathology of diverse neurodegenerative disorders. The aim of our work is to investigate the sensitivity of cultured neural and glial cells to 3-NT. We report the morphological changes detected on mouse neuroblastoma (C1300) and rat glioma (C6) cell lines cultured in a medium supplemented with different 3-NT concentrations. Western blot displayed a selective incorporation of 3-NT into a single protein that co-migrated with tubulin. Both cell lines showed morphological changes, nuclear suffering, decreased viability and growth inhibition (starting from 90 and 360 microM for C1300 and C6, respectively). Such effects were dose-dependent, though glioma cells showed severe alterations at higher 3-NT concentrations. Our results point out a higher 3-NT sensitivity in the neural cells studied in comparison with those of glial origin. The dramatic toxicity of 3-NT in neural cells suggests further investigations focused on the biochemical mechanisms at the roots of neurodegenerative diseases.