Two dosage regimens of penicillin V were compared in 327 patients with mild to moderately severe streptococcal pharyngitis. Patients fulfilling study criteria were randomly assigned to a b.i.d. or a t.i.d. dosage schedule. Those in the b.i.d. group were given 500 mg twice daily; those in the t.i.d. group were given 250 mg three times daily. Duration of therapy was ten days for both groups. Cure was based on prompt symptomatic improvement, subsidence of clinical signs, and negative throat cultures for group A beta-hemolytic streptococci. Both dosage schedules yielded similar cure rates, indicating that with penicillin V, a b.i.d. regimen is as effective as a t.i.d. regimen in treating streptococcal pharyngitis.