Background and objectives : To study the efficacy of sub-Tenon block in reducing the intensity of pain and reduction of perioperative adverse ef­fects that Occur during retinal detach­ment repair surgery under general an­esthesia. ... Materials and methods : Sixty, 60 ASA physical status I or II patients undergoing retinal detachment repair surgery were randomized into two groups, both groups received gener­al anesthesia either with sub-Tenon b!ock(using 2 ml lidocain 2% and 2 ml bupivacaine 0.5%) in the case group < /p> or without sub-tenon block in the con­trol group. Intraoperative hemody-namic changes, intraoperative compli­cations and ocular tension monitoring were recorded. Postoper­ative intensity of pain were assessed by visual analogous score (VAS). Also, occurrence of postoperative nausea and vomiting (PONV) were recorded. Result: As regard post operative pain, in group 1 (with sub-Tenon in-jection)early in the recovery, visual analogous score was less than in group 2(without sub-Tenon injection),