OBJECTIVE: The aim of this study was to evaluate the effect of mobile phone (MP) on cardiac electrical activity by examining the heart rate variability (HRV), QT, P dispersions and blood pressure (BP) while the MP is located on the precordium. METHODS: A total of 24 healthy volunteers were included in this prospective study. In the first step; 12-lead electrocardiogram (ECG) and BP recordings of the subjects without MP, while the MP is off, on, and ringing were recorded. In the second step; rhythm and BP were recorded for 30 minutes with the Holter without MP, and when the MP was "on" at the precordial location. P-wave and QT interval dispersions were measured from 12-lead ECG, while Holter 24-hour recordings were used for HRV analysis. Statistical analysis was performed using paired t test for comparison of hemodynamic and HRV variables without MP and during MP on. ANOVA for repeated measures was used to compare hemodynamic and ECG variables through baseline and 3 experimental settings: MP on, off and ringing. RESULTS: There were no statistically significant differences between the groups in the BP, heart rate, P-wave dispersion, QT dispersion and QT corrected dispersion parameters (p>0.05) in the first step of the study. In the second step, there were no significant differences between two groups in the BP, heart rate and HRV parameters (p>0.05). CONCLUSION: We conclude that MP has no effect on hemodynamic (heart rate, blood pressure) and cardiac electrical activity (P-wave and QT dispersions) parameters when it is positioned on the chest in immediate proximity to the heart, and it does not cause cardiac autonomic dysfunction examined by HRV analysis in healthy adult subjects.