Aim: To study the surgically induced astigmatism (SIA) caused by two different type main incisions in phacoemulsification. Methods: Sixty-eight eyes of 65 patients who underwent phacoemul-sification were randomly divided into two groups according to main incision type: 2.8 mm superior limbal incision (in Group 1) and 2.8 mm upper clear corneal incision (in Group 2). Surgical techniques did not differ between the groups except for the main incisions. All patients received detailed ophthalmological examination in addition to keratometry at the pre- and post-operatively. The preoperative and postoperative astigmatisms were calculated by the vector analysis method and the SIA was compared between the groups. Results: The mean SIA values were 1.3 ± 0.67 D, 0.89 ± 0.47 D, 0.77 ± 37 D in Group 1 and 1.42 ± 0.62 D, 1.15 ± 0.54 D, 0.94 ± 0.47 D in Group 2 on the first day, first week and first month postoperatively, respectively. According to the vector analysis, SIA was less in Group 1 than Group 2;although the difference was not statistically significant (p > 0.05). Conclusion: Although less astigmatism was detected in the superior limbal incision group, this difference was not statistically significant.