Objective To evaluate the safety,efficacy,predictability and stability of astigmatic keratotomy (AK) for the correction of astigmatism during anterior chamber phakic intraocular lens (ACPIOL) surgery.Methods This was a prospective case control study.Fifty-two eyes of 30 patients with 1.0 D or more of refractive astigmatism,underwent AK during ACPIOL surgery (treatment group).Twenty-three eyes of 15 patients with less than 1.0 D refractive astigmatism,underwent ACPIOL surgery only (control group).The CRAVY vector analysis of the flattening effect plotted on the target axis was used to assess the effectiveness of the treatment.Data were analyzed with repeated measure variance analysis,Wilcoxon rank sum test,Mann-Whitney U test.Results Average preoperative best corrected visual acuity (BCVA) of the treatment group was 4.69±0.24,reaching 4.81±0.15 (P=0.007)and 4.85±0.16 (P＜0.01) at 1 week and 9 months postoperatively.Average preoperative BCVA of the control group was 4.82±0.17,reaching 4.88±0.16 (P=0.261) and 4.93±0.14 (P=0.069) at 1 week and 9 months postoperatively.The average spherical equivalent (SE) of the treatment group was (-16.89±4.45)D,reaching (-0.61±1.14)D (P＜0.01) and (-0.68±1.06)D (P＜0.01) at 1 week and 9 months,respectively.Average preoperative SE of the control group was (-15.33±3.36)D,reaching (-0.57±0.89)D (P＜0.01) and (-0.77±0.70)D (P＜0.01) at 1 week and 9 months postoperatively,respectively.Eyes in the treatment and control groups showed a statistically significant refractive and corneal astigmatism reduction at the 9-month follow-up evaluation (P＜0.05).In the treatment group,the safety index was 1.03,the correction index was 79％ and the magnitude of error was -0.44 D.Conclusion AK performed during ACPIOL surgery appears to be a safe,effective and stable procedure to reduce pre-existing astigmatism,which remained consistent throughout the follow-up period.Further study is required to improve its predictability.