Aspirin and angiotensin converting enzyme (ACE) inhibitors both have beneficial effects on prognosis in patients with cardiovascular disease. For this reason, they are usually prescribed together. Some of the beneficial effects of ACE inhibitors are thought to be due to reduced degradation of bradykinin. Bradykinin enhances nitric oxide and vasodilatory prostaglandins. Theoretically, aspirin, which inhibits cyclooxygenase enzyme, may reduce bradykinin mediated prostaglandin synthesis and blunt the beneficial effects of ACE inhibitors, when used together. Although some hemodynamic studies support this hypothesis, clinical studies have conflicting results. In this article, we reviewed the possible interaction between aspirin and ACE inhibitors in light of literature findings.