Background. Heart rate variability (HRV) and skin conductance (SC) reflect autonomic activity and the balance of autonomic nervous system (ANS) which regulates involuntary physiological functions. The modulation of ANS tonic activity is a target of osteopathic manipulative treatment (OMT). The main aim of the present study was to verify whether CV4 and RR osteopathic techniques influence ANS activity, as measured by HRV and SC.