OBJECTIVE To evaluate 25-gauge pars plana vitrectomy (PPV) for primary repair of rhegmatogenous retinal detachment (RRD). METHODS This retrospective, consecutive case series included 42 eyes of 41 patients who underwent primary repair of RRD utilizing transconjunctival 25-gauge PPV without scleral buckling at the Cincinnati Eye Institute from July 2004 through January 2007. METHODS The medical records were retrospectively reviewed, and the corresponding demographic data, preoperative ophthalmic diagnoses, surgical management, and postoperative course and treatment were recorded. Main outcome measures included single surgery anatomical success, preoperative and postoperative visual acuity, and complications. RESULTS Most patients had pseudophakic RRD (36 [85.7%] of 42 eyes). The crystalline lens was present in the remaining 6 eyes (14.3%). Of 42 eyes, 28 (66.7%) had macula-on RRD, while 14 (33.3%) had macula-off RRD. Four surgeons contributed to this study, and 25-gauge PPV instrumentation, a wide-angle viewing system, endolaser photocoagulation, and gas tamponade were used in each case. The single surgery anatomical success rate was 92.9% (39 of 42 eyes). For eyes with macula-on RRD, best-corrected visual acuity was 20/50 (0.43 logMAR [logarithm of the minimum angle of resolution]) preoperatively and 20/30 (0.23 logMAR) postoperatively (P = 0.24). For eyes with macula-off RRD, best-corrected visual acuity was 5/200 (1.56 logMAR) preoperatively and 20/30 (0.23 logMAR) postoperatively (P = 0.001). Three eyes required additional surgery for final reattachment. Final reattachment was achieved in 100% of patients (mean follow-up, 8 months). CONCLUSIONS Twenty-five-gauge PPV with laser retinopexy and gas tamponade is effective for primary repair of RRD. The single operation anatomical success rate is comparable with rates reported for primary vitrectomy with 20-gauge instrumentation, scleral buckling, and combined vitrectomy/scleral buckling.