Twenty-one eyes of 21 patients with refractory glaucoma underwent glaucoma surgery involving placement of a modified Molteno implant and intraoperative application of mitomycin C. Sixteen eyes (76.2%) had an intraocular pressure (IOP) of 21 mm Hg or less after a mean follow up of 9.4 +/- 6.4 months; additional medication was needed in six eyes. Major complications included early flat anterior chamber (42.9%), implant plate erosion (9.5%), tube erosion (4.8%), late hypotony (4.8%), tube-corneal touch (4.8%), and phthisis bulbi after choroidal hemorrhage (4.8%). Only one patient had a high IOP due to decreased filtration through the implant. These results suggest that glaucoma implant surgery with the adjunctive use of mitomycin C may be useful in eyes with refractory glaucoma.