AIM: To compare therapeutic effect in surgical removal of idiopathic epimacular membrane(IEM) with transconjuctival sutureless 23-gauge(23G) vitrectomy and conventional 20-gauge(20G) vitrectomy. METHODS: Fifty-six cases 56 eyes with IEM underwent either 23- or 20-gauge vitrectomy from March 2008 to June 2011. Main outcome measures included visual acuity(VA), intraocular pressure(IOP), operative complications and surgical time．Postoperative mean follow up was 16 months. RESULTS: The VA increased three months after surgery in 23G group. The logMAR at day 1, week 1 and month 3 was 1.78±0.94, 1.51±0.88, 1.48±0.91, respectively. The differences between the three time points and preoperative baseline was significant (t=3.3917, P=0003；t=11.1779, P=0.0000; t=4.3424, P=0.0000). The VA of the three points was logMAR=2.11±1.00, 1.93±102, 164±1.00 respectively in 20G group. The differences between postoperative week 1, month 3 and preoperative baseline was significant(t=2.3578, P=0.033; t=3.5552, P=0.003). The intergroup differences at the three time point was not significant(t=0.9582, P=0.34；t=1.2761, P=0211; t=0.4897, P=0.628). The mean IOP at day 1, week 1 and month 3 in 23G group was 11.62±9.7, 15.86±6.6, 16.84±5.6mmHg while in 20G group was 18.56±7.71, 1533±5.21, 14.72±3.56mmHg, respectively. The differences of IOP at day 1 was significant(P<0.001). The mean surgical time of 23G group 41.20±7.47 minutes was significantly less than that of 20G group(52.28±7.11 minutes, P<0.001). No endophthalmitis or retinal detachment was found in both 23G and 20G group. Postoperative discomfort and intraocular inflammation were significantly reduced in the 23-gauge group. CONCLUSION: The 23G TSV system is a safe and efficient surgical technique for IEM surgery. Operating time is significantly reduced, minimizing surgery-induced trauma, and reducing the patients discomfort.