Background: The recommended duration of antibiotic treatment of tonsillopharyngitis caused by group A β-hemolytic streptococci (GABHS) with penicillin V (PenV) is mostly 10 days. However, compliance with 10-day courses is bad. Shorter therapeutic courses are necessary, especially in young children. Methods: In a prospective, randomized, multi-center study, children aged 1–17 years with acute tonsillopharyngitis and a positive culture for GABHS were treated with cefuroxime axetil (CAE) 20 mg/kg/day (max. 500 mg) b.i.d. for 5 days or with PenV 50,000 IU/kg (30 mg/kg) t.i.d. for 10 days. Patients were evaluated for clinical efficacy 2–4 and 7–9 days after the end of therapy. Throat swabs were taken 2–4 days after the end of therapy and at the first follow-up visit. Follow-up visits were carried out 7–8 weeks, 6 months and 12 months after study inclusion. Results: 1,952 patients (CAE for 5 days, 496 patients/PenV for 10 days, 1,456 patients) could be included in the intent-to-treat analysis. Two to 4 days after completion of the treatment course, the bacteriological eradication in group A (1–5 years) and group B (6–17 years) was 90.52 and 89.53% (CAE) vs. 84.13 and 84.20% (PenV), respectively; p = 0.0172; 0.0382; clinical success was 98.30% (CAE) versus 93.25% (PenV), p = 0.0017. Recurrent infections were significantly higher in younger children (group A) under both treatment regimens. Poststreptococcal sequelae (glomerulonephritis) were observed in only 1 case, in the PenV group. Conclusions: CAE b.i.d. for 5 days was at least as effective as PenV t.i.d. for 10 days. Incountries with a low incidence of rheumatic fever, CAE for 5 days can be recommended for the therapy of tonsillopharyngitis due to GABHS – also in young children.