Cefuroxime axetil was compared with amoxycillin in the treatment of acute and acute on chronic sinusitis in a multicentre general practice study. A total of 160 patients were randomized to receive 250 mg cefuroxime axetil orally twice daily, or 250 mg amoxycillin orally three times daily for 10 days. Of the 45 assessable patients with acute sinusitis 43 (96%) were cured or improved using cefuroxime axetil compared with 49 (94%) of the assessable patients in the amoxycillin-treated group. In patients with acute on chronic sinusitis, cefuroxime axetil resulted in an 80% (16/20) cure or improvement, with a 68% (13/19) response in the case of amoxycillin. Adverse events were mainly gastro-intestinal and none was considered serious in either treatment group, although three patients receiving cefuroxime axetil were withdrawn from treatment. It is concluded that cefuroxime axetil is at least as clinically efficacious as amoxycillin in the treatment of acute sinusitis in adults.