Aim: The assessment of heart rate variability (HRV) has been considered as an important non-invasive method to evaluate cardiac autonomic function. Concerning recent evidence on the relationship between impaired autonomic dysfunction and sarcoidosis, we aimed to investigate the effect of pulmonary sarcoidosis on cardiac autonomic dysfunction. Materials and Methods: This prospective study comprised of 36 participants, including 18 patients diagnosed with pulmonary sarcoidosis and 18 age-matched healthy volunteers. All participants underwent echocardiographic examination, 12-channel electrocardiography and 24-h Holter monitoring. HRV parameters were determined and compared between the groups. Results: In time domain analyses, RMSDD values significantly decreased in the patient group compared to the control group (p=0.043). The low-frequency power in frequency domain analyses between sarcoidosis patients and controls demonstrated a statistically significant difference (p=0.045). In the correlation analysis, PR duration was negatively correlated with all-time domain and frequency domain parameters as SDNN, SDANN and high-frequency values, which had a statistically significant difference (p=0.009, p=0.003, p=0.047 respectively). Corrected QT (QTc) duration was negatively correlated with all-time domain and frequency domain parameters as well. The low-frequency/high-frequency ratio was positively correlated with QTc duration.Conclusion: The patients with pulmonary sarcoidosis displayed a decrease in all HRV values reflecting diminished parasympathetic tone or blunted cardiac response to vagal modulation. This may cause cardiac outcomes such as atrioventricular conduction abnormalities, proarrhythmic tendency, ventricular arrhythmias and sudden death.