Peribulbar anesthesia is widely applied in cataract surgeries. The aim of this study was comparing the effect of using Atracourium, cis-Atracourium, and placebo as adjuvant agents to the local anesthetic substance on peribulbar-induced akinesia in cataract surgeries. The study was double-blind randomized clinical trial, among the patients candidate for the cataract surgery who were hospitalized in ocular surgery ward in Farabi Hospital between 2006 and 2007. 90 patients were subcategorized into 3 groups randomly. Group I received a mixture (8 ml) containing equal parts of Marcaine 0.5%, Lidocaine 2% and Hyaluronidase 90 IU plus 0.5 ml normal saline; group II received the mixture (8 ml) plus 0.5 ml Atracourium 5 mg, and group III received the mixture (8 ml) plus 0.5 ml cis-Atracurium with the help of peribulbar blockage technique. The score of akinesia were evaluated in the 1st, 3rd, 5th, 10th minutes after administration of the medications. 10 minute after drug administration, 25 (92.6%) reached the total akinesia with Atracourium, 23 (85.2%) with cis-Atracourium, and 23 (85.2%) with the placebo (P>0.05). Addition of low-dose Atracourium and cis-Atracourium to the anesthetic drug is recommended in order to accelerate the onset of akinesia resulted by the peribulbar block, and in order to enhance the quality of akinesia especially when Hyaloronidaze is not added.