The efficacy and safety of a 10-day course of ceftibuten oral suspension (9 mg/kg once daily) were compared with those of penicillin V (25 mg/kg/day in 3 divided doses) in children 3 to 18 years old treated for symptomatic pharyngitis and scarlet fever caused by group A beta-hemolytic streptococci (Streptococcus pyogenes). The study was prospective, randomized, multicenter and investigator-blinded; patients were randomized in a 2:1 ratio (ceftibuten:penicillin V). Overall clinical success (cure/improvement) at the primary end point of treatment (5 to 7 days posttherapy) was achieved in 97% (285 of 294) of ceftibuten-treated patients vs. 89% (117 of 132) of penicillin V-treated patients (P < 0.01). Elimination of infecting streptococci 5 to 7 days posttherapy was achieved in 91% (267 of 294) of ceftibuten-treated patients vs 80% (105 of 132) of penicillin V-treated patients (P < 0.01). A significant rise in anti-streptolysin O or anti-DNase B was observed in approximately 30% of patients in both treatment groups. No patient developed rheumatic fever or nephritis. Treatment-related adverse events were similar between the two groups; mild vomiting (2%) was most frequently reported. These data suggest that once daily ceftibuten is as safe as and more effective than three times daily penicillin V for the treatment of group A beta-hemolytic streptococcal pharyngitis.