This multicentre, double-blind, trial in subjects with severe hypertension compared the efficacy and tolerability of two parallel drug regimens: A/B (amlodipine/ benazepril: 5/20 or 10/40 mg daily, if necessary) with A (amlodipine: 5 or 10 mg daily, if necessary). The principal dependent variable was the proportion of patients achieving goal blood pressures (BP<140/ 90 mm Hg or BP<130/80 mm Hg in diabetes or chronic kidney disease) in the two groups within 6 weeks. In the 259 randomized subjects, BP control rates were higher with A/B at 2, 4 and 6 weeks (10.5, 22, and 33.6%, respectively) compared with A (5.7, 16, and 25.8 %, respectively). Corresponding trended BP reductions from baseline at 2, 4 and 6 weeks were about 5 mm Hg greater with A/B (-21 +/- 16, -26 +/- 17 and -30 +/- 17 mm Hg, respectively, compared with A (-16 +/- 17, -23 +/- 18 and 25 +/- 19 mm Hg, respectively, P<0.01). Both regimens were well tolerated; incidences of peripheral oedema at weeks 4 and 6 were similar (A/B: 13 and 20% versus A: 20 and 22%, P=not significant). We conclude that titration of amlodipine and benazepril in single-pill combinations is more effective than titration of amlodipine alone for rapid BP control in patients with severe hypertension. Journal of Human Hypertension (2010) 24, 403-409; doi: 10.1038/jhh.2009.80; published online 5 November 2009