OBJECTIVES: The pathogenesis of primary Raynaud\'s phenomenon (RP) seems to be multifactorial and autonomic nervous dysfunction is one factor. Heart rate variability (HRV) is one of the most reliable parameters to demonstrate autonomic dysfunction. Our aim was to evaluate the time-domain HRV in patients with primary RP. METHODS: A time analysis of HRV was performed in patients with primary RP and age- and gender-matched healthy controls. The results of the study and control group were compared. RESULTS: Thirty patients with primary RP [all men, median (IQR) age: 21 (2) years) and 31 age- and gender-matched healthy controls (median (IQR): 21(3) years] were enrolled in the study. We found a statistically significant difference between the primary RP patients and control subjects in terms of time-domain HRV parameters (p < 0.05 for all). CONCLUSION: Our study showed the presence of autonomic nervous dysfunction of heart function in patients with primary RP.