Objective: The aim of this investigation was to evaluate the efficacy of reduction in intraocular pressure (IOP) and complications in ab externo superpulse carbon dioxide laser-assisted trabeculectomy. Background: Reduction of IOP remains the immediate goal of glaucoma treatment. Although trabeculectomy has been considered the gold standard for the surgical treatment of glaucoma, many complications are associated with this procedure. Laser surgery has been studied as an alternative way to control IOP in glaucoma. Materials and Methods: Sixty adult albino rabbits were enrolled in this study. The animals underwent one unilateral surgery of either trabeculectomy or ab externo superpulse carbon dioxide laser-assisted trabeculectomy and were divided into two subgroups, control or experimental. Follow-up examinations included ocular anterior segments, filtration blebs and IOP. Five eyes in each group were analyzed histologically one month postoperatively. Results: Anterior chamber hyphema in the laser group was milder than that in the surgery group, and disappeared on the third day. In the surgery group, it disappeared by the end of the first month. Filtration blebs in the laser group formed earlier than in the surgery group. Comparing the laser group and the surgery group, IOP values in the laser group were more stable. Histological examination showed that the sclera tract was blocked by scar tissue, inflammation had infiltrated, and the anterior chamber angle had adhered in the surgery group. Conclusions: Ab externo superpulse carbon dioxide laser-assisted trabeculectomy was suggested as a feasible technique to control IOP with the advantages of more steady IOP reduction and fewer complications.