Chronic hypertension is a well established risk factor for the development of cardiovascular disease; however, its prognostic significance after a non-ST-segment elevation acute coronary syndrome remains to be established. Data from 15,414 patients included in six randomized Thrombolysis in Myocardial Infarction (TIMI) trials (TIMI 3B, TIMI 11A, TIMI 11B, TIMI 12, the Orbofiban in Patients With Unstable Coronary Syndromes [OPUS]-TIMI 16, and the Treat Angina With Aggrastat and Determine Cost of Therapy With an Invasive or Conservative Strategy [TACTICS]-TIMI 18) were analyzed. A history of hypertension was present in 10,998 (71.35%) patients; comorbidities and higher TIMI risk scores were more likely in these patients. However, positive troponin and ST-segment deviations were less frequent among hypertensive patients. After multivariate analysis, the history of hypertension was associated with more adverse outcomes, specifically the composite end point of death/myocardial infarction at 30 days and 1 year (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.31-1.81; p<0.001 at 1 year) than in patients without this history. An independent relationship was also observed with mortality (OR 1.70, 95% CI 1.34-2.16; p<0.001 at 1 year), myocardial infarction (OR 1.50, 95% CI 1.23-1.82; p<0.001 at 1 year), recurrent ischemia (OR 1.24, 95% CI 1.11-1.38; p<0.001 at 1 year), and major bleeding (OR 1.45, 95% CI 1.03-2.06; p=0.036 at 30 days). It was concluded that chronic hypertension remains an independent marker for major short- and long-term cardiac adverse outcomes after non-ST-segment elevation acute coronary syndrome.