Aim: To compare sutureless 23-gauge versus sutureless 20-gauge system for pars plana vitrectomy as regarding safety and efficacy in pars plana vitrectomy. Patients and methods: A prospective non –randomized interventional study comparing the two vitrectomy systems in a group of disease requiring uncomplicated vitreoretinal surgery was carried out at Nour- EL–Hayaha Eye Center (Cairo) between August, 2015 and June, 2017. Patients were divided into two groups. Group (A) 23 –gauge group: included thirty eyes of 20 patients, ten patients had bilateral pars plana vitrectomy (PPV), while in group (B): included twenty five eyes of 20patients, five patients had bilateral operations. Ocular examinations included measurements of best corrected visual acuity (BCVA) at a distance using a logarithm of the minimum angle of resolution (logMAR) scale, refractive status using an autorefractometer (KR-8100; Topcon corporation, Tokyo, Japan), IOP  was measured  pre and postoperative by Goldman applanation tonometry (CT-80; Topcon corporation, Tokyo, Japan), and fundus evaluation using an indirect ophthalmoscope were obtained. Surgical indication, outcome, intraoperative and postoperative complications were evaluated. Patients with vitreoretinal pathology such as preretinal membrane, vitreous haemorrhage with fibrovascular proliferation (FVP), persistent vitreous haemorrhage  ,tractional retinal detachment,  persistent macular edema or macular hole were enrolled in this study. Furthermore, postoperative subjective pain, conjunctival injection, retinal function and situation of retina were evaluated. Follow up was performed at the 1st day, 1st, 2nd week and 1st, 3rd and 6th month after surgery. Results: All the fifty five eyes completed the regularly follow up visits up to 24 months. 55 eyes of 40 patients divided into 2 groups: Group (A) 30 eyes of 20 patients (6 males, 30% and 14 females, 70%, the mean age of the participants ± SD was 54.62±3.12 years Range: 46-60 years;were treated with 23-gauge PPV .While in Group (B) twenty five eyes of 20 patients (13 males, 65% and 7 females, 35%, the mean age of the participants ± SD was 49.72±3.06 years Range: 50-58 years; were treated with sutureless 20-gauge PPV. The mean age of both groups ± SD was 52.67±5.14 years (Range: 47-62 years). Statistically, the differences between both groups regarding age and sex were insignificant. Conclusion: Advantages of sutureless vitrectomy include a reduction in operating time, less subconjunctival adhesion facilitating any subsequent vitreoretinal surgery or filtration surgery