Ten-day, double-blind, randomized, parallel treatment regimens of loracarbef (200 mg capsule twice daily or 15 mg/kg/day oral suspension in two divided doses up to a maximum of 375 mg/day; n = 169) and penicillin V (250 mg capsule four times daily or 20 mg/kg/day suspension in four divided doses up to a maximum of 500 mg/day; n = 175) were compared in the treatment of group A beta-haemolytic streptococcal (GABHS) pharyngitis and tonsillitis. Post-therapy clinical responses were similar for evaluable patients in both treatment groups: 97.4% of the loracarbef group (101/115 patients cured and 11/115 improved) and 96.0% of the penicillin group (101/124 patients cured and 18/124 improved). A statistically significant difference in the pathogen elimination rate was noted between treatment groups: post-therapy throat cultures were negative for GABHS in 94.8% (109/115) of loracarbef-treated patients compared with 87.1% (108/124) of penicillin-treated patients (p = 0.040). Loracarbef and penicillin V were comparable in terms of safety. Headache and nausea/vomiting were the most common events reported during therapy (nausea/vomiting were slightly less common in the loracarbef group). Three patients in each group were discontinued from the study due to drug-related adverse events; one due to rash in the loracarbef group and one due to rash and one due to vomiting in the penicillin group. These data support the conclusion that loracarbef twice daily is more effective in eradicating GABHS than penicillin V four times daily, and the two drugs are comparable in safety and clinical efficacy in the treatment of GABHS pharyngitis and tonsillitis.