The effects of β-blockade in addition to more specific renin-angiotensin system (RAS) blockers on blood pressure (BP) in patients with diabetes are described. After washout of medications other than angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, patients were titrated to a BP level <130/80 mm Hg using therapy with carvedilol 6.25 to 25 mg bid (n=498) or metoprolol tartrate 50 to 200 mg bid (n=737). At the end of the β-blocker titration period, a BP level <130/80 mm Hg was achieved in 37% of carvedilol-treated and 36% of metoprolol-treated participants who continued to receive a renin-angiotensin system blocker. In the approximately 60% of participants in whom a BP level <130/80 mm Hg was not attained with renin-angiotensin system blockade plus β-blockade, hydrochlorothiazide was added in 43% and 44% of carvedilol and metoprolol groups, respectively; 25% (both arms) also required a calcium channel blocker. Among those in whom goal BP was not achieved, 42% of carvedilol- and 40% of metoprolol-treated participants were not titrated to the highest dose of β-blocker. The use of carvedilol compared with metoprolol did not effect glycemic control.