OBJECTIVE: To assess the impact of early hypertension (HT) control on occurrence of subsequent major cardiovascular events in those with diabetes and recent-onset HT. RESEARCH DESIGN AND METHODS: Study subjects were 15,665 adults with diabetes but no diagnosed coronary or cerebrovascular disease at baseline who met standard criteria for new-onset HT. Poisson regression models assessed whether adequate blood pressure control within 1 year of HT onset predicts subsequent occurrence of major cardiovascular events with and without adjustment for baseline Framingham Risk Score (FRS) and other covariates. RESULTS: Mean age was 51.5 years, and mean blood pressure at HT onset was 136.8/80.8 mmHg. In the year after HT onset, mean blood pressure decreased to 131.4/78.0 mmHg and was <130/80 mmHg in 32.9% of subjects and <140/90 mmHg in 80.2%. Over a mean follow-up of 3.2 years, age-adjusted rates of major cardiovascular events in those with mean 1-year blood pressure measurements of <130/80, 130-139/80-89, and >/=140/90 mmHg were 5.10, 4.27, and 6.94 events/1,000 person-years, respectively (P = 0.004). In FRS-adjusted models, rates of major cardiovascular events were significantly higher in those with mean blood pressure >/=140/90 mmHg in the first year after HT onset (rate ratio 1.30 [95% CI 1.01-1.169]; P = 0.04). CONCLUSIONS: Failure to adequately control BP within 1 year of HT onset significantly increased the likelihood of major cardiovascular events within 3 years. Prompt control of new-onset HT in patients with diabetes may provide important short-term clinical benefits.