To describe a modified simple iris suture for pupillary dilation technique during vitrectomy in cases with a miotic pupil.Four translimbal incisions were created with a sharp straight blade at 1∶30,10∶30,4∶30,and 7∶30 o’clock,respectively.The straight needle of 10-0 polypropylene suture and a Sinskey IOL hook was used to displace the pupillary margin toward the limbus.In 3 cases,four sutures caused a 6-mm to 9-mm square-shaped pupil,and the pupil was allowed to return to a smaller size at the end of the operation.It is simple and may reduce postoperative complications.