There are no or very few studies in the literature on the effects of golf on heart rate and its parameters. The purpose of the study was to evaluate the effects of a precision sport, golf, on heart rate variability (HRV). The study population consisted of six high-level golfers aged 25 to 40 years, without cardiac disease. HRV was studied three hours before a golf competition, during the four hours of the competition and three hours after the match was over. The following parameters of HRV were calculated during 12 games of golf: mean heart rate (HR), standard deviation of the mean RR intervals (SDNN), root mean square of successive differences in RR intervals among consecutive normal beats (rMSSD), percent differences between normal RR intervals that are greater than 50 ms computed over the entire 24-hour recording (pNN50), low-frequency amplitude (LF), high-frequency amplitude (HF) and LF/HF ratio: ratio of low-to-high frequency power. Analysis of the results indicates significant variations of all parameters which occur just at the beginning of the game, persist throughout the match and remain three hours after its completion: heart rate is increased; total HRV is decreased but parameters reflect parasympathetic activity; pNN50, rMSSD and 1-117 are principally decreased. In conclusion, golf significantly affects HRV just at the beginning of golf competition, probably because of stress. These changes progressively decrease but they are still significant three hours after the end of the competition.