In order to evaluate the clinical efficacy and tolerance of cefpodoxime proxetil, compared with that of amoxicillin in the treatment of acute bacterial maxillary sinusitis, a randomized, double-blind, parallel group comparative study was performed. A total of 286 adults patients were included at 12 centres, each treatment group consisting of 143 patients. Each patient was treated for 10 days and observed before and after treatment. The observations included clinical, roentgenological, bacteriological and laboratory examinations. At inclusion, the most common pathogens were Haemophilus influenzae (24%) and Streptococcus pneumoniae (17%). In the per protocol analysis, 117 patients in the cefpodoxime group and 113 in the amoxicillin group were evaluable for clinical efficacy. The clinical response rates were 96% and 91%, respectively. The corresponding figures in the intent-to-treat analysis were 130 and 128 patients, with clinical response rates of 93% and 88%, respectively. Cefpodoxime proxetil proved clinically as effective as amoxicillin in the treatment of acute bacterial maxillary sinusitis. It was more effective in eradicating H. influenzae and was more efficient in improving the radiological score. Adverse events were reported in 20% of cefpodoxime cases and in 16% of amoxicillin cases. There was no statistically significant difference between the groups.