Previous studies have shown that labetalol, a new alpha- and beta-adrenergic antagonist, is relatively safe for the treatment of hypertension in patients with chronic obstructive pulmonary disease (COPD). This multicenter study was designed to evaluate its effects in hypertensive patients with asthma and propranolol sensitivity. Hypertension was successfully controlled in 18 of 21 patients who received labetalol in increasing doses, up to 1,200 mg/day. The decrease in mean FEV1 (1.5 percent) two hours after the highest dose of labetalol was not statistically significant, although there was a gradual decline in mean baseline FEV1 during the four-week treatment period. Antihypertensive agents other than adrenergic antagonists should be considered for the management of hypertension in patients with asthma, especially those with marked reversibility of airflow. If treatment with beta-adrenergic antagonists is indicated, labetalol is recommended over other currently available agents.