Study design: Prospective cohort study. Objectives: To characterize the cerebrospinal fluid (CSF) concentrations of glial fibrillary acidic protein, neuron specific enolase (NSE), S-100b, tau and neurofilament heavy chain (NFH) within 24 h of an acute traumatic spinal cord injury (SCI), and to correlate these concentrations with the baseline severity of neurologic impairment as graded by the American Spinal Injury Association impairment scale (AIS). Methods: A lumbar puncture was performed to obtain CSF from 16 acute traumatic SCI patients within 24 h post injury. Neurological examinations were performed within 24 h of injury and again at 6 or 12 months post injury. The correlations between the CSF concentrations and initial AIS were calculated by using Pearson correlation coefficients. In addition, an independent Student's t-test was used to test for differences in CSF concentrations between patients of different AIS grades. Results: The CSF NSE concentrations were significantly correlated with the baseline neurologic impairment being either 'motor complete' (AIS A, B) or 'motor incomplete' (AIS C, D) (r ¼ 0.520, Po0.05). The mean S-100b concentration in motor complete patients was significantly higher compared with motor incomplete patients; 377.2 mg l À1 (s.d. ± 523 mg l À1 ) vs 57.1 mg l À1 (s.d.±56 mg l À1 ) (Po0.05), respectively. Lastly, the mean NFH concentration in motor complete patients was significantly higher compared with motor incomplete patient, 11 813 ng l À1 (s.d.±16 195 ng l À1 ) vs 1446.8 ngl À1 (s.d.±1533 ng l À1 ), (Po0.05), respectively. Conclusion: In this study we identified differences in the structural CSF biomarkers NSE, S-100b and NFH between motor complete and motor incomplete SCI patients. Our data showed no clear differences in any of the protein concentrations between the different AIS grades.