Dilevalol combines vasodilation due to selective β2 agonism and nonselective β antagonism. We studied 311 patients randomized to dilevalol and 138 to metoprolol in a multicenter trial. After a 4-week placebo washout, dilevalol was titrated from 200 to 1,600 mg once daily and metoprolol from 100 to 400 mg to a goal supine diastolic blood pressure < 90 and ≥10 mm Hg decrease from baseline. Responders were followed for 1 year. The average age of patients was 51 years; 72% were men and 54% were white. Both drugs reduced blood pressure effectively to a similar level. Fewer patients discontinued dilevalol than did those taking metoprolol (9 vs 16%; p < 0.03). More metoprolol-treated patients withdrew because of depression (6 vs < 1%; p = 0.03) and impotence (5 vs < 1%; p = 0.03). Lipoprotein levels before and after treatment were measured in 99 patients treated for 53.5 weeks with dilevalol (mean dose 438 mg). Dilevalol increased high-density lipoprotein (HDL) cholesterol by 2.5 mg/dl to 47.2 (p = 0.05), reduced lowdensity lipoprotein (LDL) cholesterol by 2.5 mg/dl, increased HDL/LDL by 0.03, and decreased total cholesterol/HDL cholesterol by 0.18. Triglycerides increased by 21 mg/dl (p = 0.06). In patients with an initial HDL cholesterol < 35 mg/dl, dilevalol increased it by 9 mg/dl. In patients treated with metoprolol, the only significant change (p = 0.02) was a 41.9-mg/dl increase in triglyceride levels. It is concluded from this trial that dilevalol is an effective antihypertensive agent, may have a more favorable side-effect profile than metoprolol and may increase HDL cholesterol in hypertensive patients with low HDL cholesterol. © 1989.