Fifteen patients with 20 episodes of persistent corneal ulceration, resistant to conventional therapy, were treated with topical autologous fibronectin. Thirteen corneal ulcers (eight patients) developed following penetrating keratoplasty, three patients had mucous membrane pemphigoid, two patients had herpetic keratitis and one each had Sjögren's syndrome and a trophic corneal ulcer. A standard protocol for fibronectin administration was followed. This therapy healed 16 of the 20 ulcers after a mean duration of treatment of 2.3 months. Corneal ulceration associated with mucous membrane pemphigoid failed to respond to fibronectin. Corneal ulcers which recurred after cessation of fibronectin responded to reintroduction of this therapy. Topical fibronectin is an effective therapy for refractory corneal ulceration and is free of major side effects.