Aim:To investigate the effects of early surgery on electrocardiographic parameters in patients with aneurysmatic subarachnoidal hemorrhage by comparing the cardiac parameters between the electrocardiographies of normal individuals by performing electrocardiography on 2nd and 8th days before and after surgeryMaterial and Methods:Eighteen patients with aneurysmatic subarachnoidal hemorrhage (as study group) and 22 healthy subjects (as control group) were enrolled to this study. Demographics and electrocardiographic data of the participants were collected and compared between the groups. The analyzed electrocardiographic data included HR, QRS duration, Pmax, Pmin, PWD, QT, QTc, Tp-e, JT, JTc, Tp-e/QT, Tp-e/QTc, Tp-e/JT and Tp-e/JTc. Preoperative and postoperative 2nd day and postoperative 8th day values were comparedResults:Preoperative QT, QTc, JT, JTc, Pmax and Pmin values of patients with aneurysmatic subarachnoidal hemorrhage were found to be significantly higher than those of healthy subjects. There were no significant differences in 2th and 8th day electrocardiographic parameters of the groupsConclusion:We deduced that early and successful surgery of subarachnoid hemorrhage could alleviate electrocardiographic changes and decrease the requirement of cardiac interventions in subjects with subarachnoid hemorrhage