Autonomic dysfunction in hemodialysis patients is one of the components of uremic neuropathy. In this prospective study, we investigated the effect of renal transplantation on uremic autonomic dysfunction with long-term time-domain and frequency-domain heart rate variability. Fourteen hemodialysis patients (10 male, 4 female; mean age 33 +/- 11 (range 16-50) years) were examined before and at the early after transplantation period (mean 4.6 +/- 1.5 (range 3-7. 5) months). The mean time spent on hemodialysis was 16.7 +/- 15.6 (range 6-65) months. In time-domain analysis, significant increases in all parameters except pNN50 (SD, SDANN, SDNN, rMSSD) were observed after renal transplantation (p < 0.01). In frequency-domain analysis, low-frequency (LF) (0.04-0.15 Hz) and high-frequency (HF) (0.15-0.40 Hz) spectral power were found to be significantly increased after renal transplantation (4.54 +/- 1.04 vs. 12.58 +/- 8. 69 for LF (p = 0.005), 2.80 +/- 1.0 vs. 6.50 +/- 3.55 for HF (p = 0. 005)), but the LF/HF ratio was not different from a pretransplant period (1.71 +/- 0.349 vs. 1.85 +/- 0.49, p = 0.26). It was concluded that autonomic dysfunction in hemodialysis patients is reversible and renal transplantation reverses the sympathetic and parasympathetic autonomic dysfunction simultaneously and at a relatively early stage.