Heart rate variability (HRV) gives information on the sympathetic-parasympathetic autonomic balance. The aim of the study was to analyze sympathovagal balance after acute spinal cord injury (SCI), demonstrated by linear measures in time and frequency domain of HRV and to analyze the effect of corticosteroids on HRV parameters in SCI. The study included 40 tetraplegic patients with acute SCI and 40 healthy subjects as control group. In the SCI group, 29 patients received and 11 patients did not receive corticosteroid therapy. All patients underwent 24-hour Holter monitoring for evaluation of HRV. Cardiac autonomic balance was evaluated by analysis of HRV in time and frequency domain. Sympathovagal balance (LF/HF) was significantly reduced in the groups of acute SCI patients, both with and without corticosteroid therapy, as compared with controls. However, there was no statistically significant difference between the two SCI groups (1.74 (0524) with and 1.75 (0534) without corticosteroid therapy). This study showed the sympathovagal balance to be altered in the acute phase of cervical spinal cord trauma. Finally, there was no effect of corticosteroid therapy on HRV parameters in SCI patients.