INTRODUCTION: Clomiphene (diethylethanamine structure) is an anti-estrogen agent that is often used for ovulation induction in the treatment of infertility. Tamoxifen, another anti-estrogen agent of similar chemical structure, has been shown to prolong the QT distance. The aim of this study was to evaluate superficial ECG changes and especially QT, QTc and Tp-e intervals in patients under clomiphene treatment. METHODS: Forty-two female patients were included in the study. Clomiphene citrate 50 mg daily for 5 days was started on the day of cycle 3-7. The electrocardiograms of the patients were reached before treatment and on the day of peak luteinizing hormone increase. QRS duration, QTc interval, Tp-e, Tp-e / QT ratio and Tp-e / QTc ratio analysis were performed with MATLAB program in digital environment. Paired sample T and Wilcoxen Sum Rank test were used. RESULTS: When the basal level and post-treatment values were compared, no significant difference was observed in terms of Tp-e interval, QTc interval, QRS duration, Tp-e / QT and Tp-e / QTc ratio. Basal level versus clomiphene citrate values; Tp-e: 95.90 +- 19.50 milliseconds [ms] versus 103.30 +- 16.55 ms, QTc: 460.25 +- 30.08 ms to 430.52 +- 25.19 ms, QRS duration: 102.10 +- 14.98 ms to 109.70 +- 13.61 ms, Tp-e / QT: 0.24 +- 0.04 versus 0.25 +- 0.02, Tp-e / QTc: 0.20 +- 0.03 versus 0.21 +- 0.02 (p> 0.05). DISCUSSION AND CONCLUSION: Our study showed that clomiphene citrate had no effect on QT distance, did not carry increased proarrhythmic risk and could be used safely in ovulation induction.