AIM: To compare surgically induced astigmatism (SIA) following horizontal rectus muscle recession surgery between suspension recession with both the “hang-back" technique and conventional recession technique.METHODS:Totally, 48 eyes of 24 patients who had undergone horizontal rectus muscle recession surgery were reviewed retrospectively. The patients were divided into two groups. Twelve patients were operated on by the hang-back technique (Group 1), and 12 by the conventional recession technique (Group 2). SIA was calculated on the 1^st wk, 1^st and in the 3^rd mo after surgery using the SIA calculator.RESULTS: SIA was statistically higher in the Group 1 all postoperative follow-up. SIA was the highest in the 1^st wk, and decreased gradually in both groups.CONCLUSION: The suspension recession technique induced much more SIA than the conventional recession technique. This difference also continued in the following visits. Therefore, the refractive power should be checked postoperatively in order to avoid refractive amblyopia. Conventional recession surgery should be the preferred method so as to minimize the postoperative refractive changes in patients with amblyopia.