The GERD pathogenesis may be associated with disturbances of the autonomic nervous system (ANS), which can be revealed using heart rate variability studies (HRV). The aim of presented study was to estimate the circadian ANS activity in 24-hour HRV recordings in GERD patients, both in non-erosive form (NERD), and with erosive, inflammatory changes in the esophagus (ERD patients). Our results demonstrated disturbances in the parasympathetic ANS part, but they also delivered the proofs for possible sympathetic disorder. That is why the autonomic neuropathy in GERD patients may have mixed character.