Twelve patients with failed or failing filtering blebs were treated by transconjunctival needle revision of the bleb. Seven of these received 5-fluorouracil as an adjunct. Intraocular pressure decreased from 31.3 +/- 8.8 mm Hg (range, 20 to 47 mm Hg) to 17.0 +/- 3.7 mm Hg (range, 8 to 22 mm Hg). The length of follow-up ranged from two to 31 months. The results in 11 of 12 patients (91.6%) were satisfactory, defined by an intraocular pressure of 22 mm Hg or less, with or without antiglaucoma medications, and requiring no subsequent procedures for control of intraocular pressure. The success rates and overall pressure lowering effect of the seven patients receiving and the five patients not receiving 5-fluorouracil were similar. However, most patients receiving 5-fluorouracil were thought to be at higher risk for surgical failure. Complications of needle revision were minor and resolved without sequelae. We advocate the consideration of transconjunctival needle revision with or without the use of 5-fluorouracil as a useful therapeutic modality in the management of the failed or failing filtering bleb.