AIM: To report the effectiveness and safety of primary 23-Gauge (G) vitreoretinal surgery for rhegmatogenous retinal detachment (RRD). METHODS: In this retrospective study, 49 eyes of 49 consecutive patients who underwent primary 23-G transconjunctival sutureless vitrectomy (TSV) for RRD between January 2007 and July 2009 at our institution were evaluated. RESULTS: Mean follow-up time was 8.9±7.7 months. Retinal reattachment was achieved with a single operation in 47(95.9%) of 49 eyes. In two eyes (4.1%), retinal redetachment due to new breaks was successfully treated with reoperation using the 23-G TSV system. Mean logMAR visual acuity was 2.01±0.47 preoperatively and 1.3±0.5 postoperatively (P<0.001, Paired t-test). Mean preoperative intraocular pressure (IOP) was 14.1±2.8mmHg. Mean postoperative IOP was 12.3±3.6mmHg at 1 day, 13.1±2.1mmHg at 1 week, 14.3±2.2mmHg at 1 month. Iatrogenic peripheral retinal break was observed in 1 eye (2.0%) intraoperatively. No sutures were required to close the scleral or conjunctival openings, and no eyes required convertion of surgery to 20-G vitrectomy. CONCLUSION: Primary 23-G TSV system was observed to be effective and safe in the treatment of RRD.