We compared the efficacy of mitomycin-C (MC) with that of 5-flu-orouracil (5-FU) as adjunctive therapy in glaucoma filtration surgery in rabbits. Filtration surgery was performed in each left eye of 34 rabbits, which were divided into 4 groups. Seven eyes in group 1 (plain) received no adjunctive therapy. Nine eyes in group 2 (5-FU) received postoperative subconjunctival injections of 5 mg 5-FU (0.5 ml, 10 mg/ml) from postoperative days 1 through 5. Five eyes in group 3 received intraoperative soaking of 0.25 mg/ml MC for 5 min. Thirteen eyes in group 4 (MC ± MC) received the same treatment as group 3, with the addition of a single postoperative subconjunctival injection of 0.01 mg MC (0.1 ml. 0.1 mg/ml) on postoperative day I. The fellow right eye was unoperated in each group. Successful intraocular pressure (10P) control, defined as an IOP difference between the operated and the fellow eye of >3 mm Hg, occurred for a longer time period in the MC ± MC group (p < 0.00001). The median days of bleb survival in groups 1, 2, 3, and 4 were 6, 8, 5, and 32 days, respectively (p = 0.00002). The combined use of MC intraoperative and postoperatively appears to promote the success of glaucoma filtration surgery in rabbits, and this regimen deserves further clinical study.