Non-selective nonsteroidal anti-inflammatory drugs (NSAIDs) have long been known to cause gastrointestinal and renal toxicity. More recently, adverse cardiovascular effects have been associated with the selective COX-2 inhibitors. However, current studies that show an increased cardiovascular risk with non-selective NSAIDs raise the question of the exclusive contribution of COX-2 to this type of toxicity. Aldosterone, a key cardiovascular hormone, can induce deleterious effects, such as myocardial fibrosis and vascular stiffening. Non-selective NSAIDs inhibit the metabolism of aldosterone in vitro by human renal tissue, predicating an increased plasma aldosterone concentration in vivo. The question remains whether inhibition of aldosterone metabolism by non-selective NSAIDs is a casual or causal factor in NSAID-induced cardiovascular toxicity.