Abstract Introduction Ranolazine is an antianginal drug and also exhibits antiarrhythmic effect by affecting action potential time, refractory period, and repolarization reserve. We evaluated the effect of ranolazine therapy on myocardial repolarization parameters (Tp‐e, QT, QTc intervals, Tp‐e/QT, and Tp‐e/QTc ratios), index of cardiac electrophysiological balance (iCEB) (QT/QRS, QTc/QRS) and P‐wave dispersion (PWD) in patients with stable coronary artery disease (CAD). Methods This study included 175 patients, aged between 35 and 90 years who were followed with stable CAD for at least 3 months. Ninety patients had been receiving ranolazine for at least 1 month, and 85 patients had never received ranolazine. All patients' basic demographic data, risk factors, medications, and echocardiographic parameters recorded. Myocardial repolarization parameters, P‐wave times, and PWD were analyzed from 12 lead electrodes. Results There was no variation between the groups in terms of basic demographic parameters and CAD risk factors. Tp‐e interval (87.3 ± 14.4 vs. 90.8 ± 12.4 msn, P