OBJECTIVE To describe the initial experience, effectiveness, and safety profile of 23-gauge instrumentation for a variety of vitreoretinal conditions. METHODS Single-center, retrospective, noncomparative, consecutive interventional case series. METHODS Seventy-seven eyes of consecutive patients who underwent 23-gauge transconjunctival vitrectomy surgery by a single surgeon at the Manhattan Eye, Ear, and Throat Hospital from October 2004 through October 2005. METHODS All patients underwent 3-port 23-gauge vitrectomy using Dutch Ophthalmic Research Corporation instrumentation and an Alcon Accuris Vitrector. METHODS Postoperative visual acuity at months 1 and 3, intraoperative and postoperative complications, and operative time. RESULTS Mean acuity improved from 20/190 at baseline to 20/108 (P<0.0001) and 20/74 (P<0.0001) at months 1 and 3, respectively. By diagnosis, patients with epiretinal membrane (n = 20) improved from 20/124 to 20/93 (P = 0.0046), macular hole (n = 18) from 20/174 to 20/57 (P = 0.0007), rhegmatogenous retinal detachment (RD) (n = 14) from 20/248 to 20/51 (P = 0.0004), tractional RD (n = 12) from 20/175 to 20/62 (P = 0.0159), nonclearing vitreous hemorrhage (n = 12) from 20/1345 to 20/189 (P = 0.0004), vitreomacular traction (n = 4) from 20/145 to 20/124 (P = 0.7525), and retained lens fragments (n = 4) from 20/308 to 20/140 (P = 0.0972). One patient who underwent diagnostic vitrectomy had stable 20/50 acuity. Two patients had hypotony on postoperative day 1, 1 patient required a sutured sclerotomy intraoperatively, and no patients developed choroidal effusions. No intraoperative tears were noted. Surgical times collected on 17 patients during the final month of the study demonstrated a mean opening time (range) of 103 seconds (70-162), mean closing time of 75 seconds (17-470), and net operating time of 24.1 minutes (7.1-74.6). CONCLUSIONS Twenty-three-gauge instrumentation is effective for a variety of vitreoretinal surgical indications. The safety profile compared favorably with published rates for 25-gauge systems.