PURPOSE: To report a case of malignant glaucoma after diode laser cyclophotocoagulation. METHOD: Case report. RESULTS: A 45-year-old man with uncontrolled secondary glaucoma in his right eye after corneoscleral graft and cataract extraction underwent diode laser cyclophotocoagulation, The right eye was aphakic, with an intact posterior capsule. Two weeks later, the patient presented with blurred vision, edematous cornea, and flat anterior chamber. The posterior capsule was touching the endo thelium, Intraocular pressure was 20 mm Hg, Repeated Nd:YAG laser capsulotomy was effective in reversing the malignant glaucoma attack, and the anterior chamber deepened. CONCLUSION: Malignant glaucoma can occur after diode laser cyclophotocoagulation. (Am J Ophthalmol 1999;127:467-469, (C) 1999 by Elsevier Science Inc. All rights reserved.).