Supine office blood pressures (SOBP) and 24-hour automated ambulatory blood pressure monitorings (AABPM) showed blood pressure reductions from a stable baseline to active treatment with 120-, 240-, and 480-mg doses of a new verapamil QD capsule (solid-spheroidal-oral once-daily drug-absorption system: (SODAS) in patients with mild-to-moderately severe (diastolic blood pressures 95-119 mm Hg) essential hypertension. Reductions were documented at 24 hours, hourly, and by the 24 hour average, using SOBP and AABPM, after the once-daily verapamil administration. Both SOBP and the 24-hour average by AABPM were significantly reduced from baseline by active verapamil treatment of 120-, 240-, and 480-mg doses. In comparison to verapamil QD (0 mg), blood pressure reductions from baseline to active treatment were significant at the 240- and 480-mg doses but not at the 120-mg dose. There was a significant linear dose response. This verapamil formulation (SODAS) was effective throughout the 24-hour period after once-daily dosing.