Four adult patients with unstable angina were treated with intravenous nitroglycerin in the coronary intensive care unit. All four patients experienced an acute gouty flare while receiving or within 12 hours of discontinuing intravenous nitroglycerin. Serum uric acid levels ranged from 400 to 550 mumol/L at the time of the attack. In one patient, serum uric acid levels were followed while he was receiving intravenous nitroglycerin and were noted to increase nearly 60 mumol/L. It was speculated that the alcohol content of intravenous nitroglycerin preparations may alter serum uric acid levels and thus precipitate acute gouty flares in patients who are at increased risk for gout.