Aim: We aimed to detect the predictive value of CS distal delay interval for differentiating the left from right sided PVCs. Methods: We included 137 patients with symptomatic frequent premature ventricular contractions (PVCs) who underwent successful catheter ablation retrospectively (67 male, 70 female; mean age 46.0 ± 16.2 years). Patients were classified into two groups as left sided and right sided PVCs. Decapolar catheters were placed in the coronary sinus before the procedure. CS distal delay interval (Q-CSd) was measured as the interval from onset of earliest QRS complex of premature ventricular contractions in 12 lead ECG to distal CS EGM signal. Results: CS distal delay interval was found to be significantly lower in left sided PVCs. The cutoff value of CS distal delay interval obtained by ROC curve analysis was 48,5 ms for prediction of right sided origin (sensitivity: 91,5%, specificity: 85.9%). The area under the curve (AUC) was 0.911 (p<0.001). Conclusion: CS distal delay interval is a novel and simple measurement for accurately differentiating the left from right sided PVCs. The use of this simple measurement could be beneficial for decreasing ablation duration, radiation exposure and the number of arterial or venous punctures.