Objective: To determine the safety of a single intravitreal injection of triamcinolone acetonide (4 mg) in patients with subfoveal choroidal neovascularization caused by age-related macular degeneration. Methods: A double-masked, placebo-controlled, randomized clinical trial was conducted at a public tertiary referral eye hospital. Patients participating had age-related macular degeneration with evidence of choroidal neovascularization, any part of which was classic; age older than 59 years; and best-corrected visual acuity of 20/200 or better. Eyes were assigned to active study treatment or to placebo. Intraocular pressure and cataract grading were performed every 6 months for 3 years. Adverse events, from mild to vision-threatening or life-threatening, were recorded as procedure-related or corticosteroid-related. Results: Seventy-five eyes were assigned to study treatment and 76 eyes to placebo. There were no moderate or severe adverse events related to the surgical procedure in either group. Triamcinolone-treated eyes had a significantly increased risk of developing mild or moderate elevation of the intraocular pressure. Topical glaucoma medication reduced intraocular pressure to acceptable levels in all patients. There was significant progression of cataract in the triamcinolone-treated eyes. Conclusion: Despite a significant adverse event profile, intravitreal triamcinolone is generally well tolerated by the human eye as long as patients are carefully followed up by their surgeon and treated appropriately, when necessary.