A total of 102 children with recurrent otitis media or therapeutic failure after treatment with phenoxymethyl penicillin were entered into a double-blind study with parallel groups, comparing treatment with amoxycillin/clavulanate suspension (Spektramox) for 7 days with amoxycillin suspension (Imacillin) for 10 days. Bacterial and clinical investigations were performed. A total of 91 patients were evaluated for efficacy at the first follow-up visit (10-12 days after start of treatment). Amoxycillin/clavulanate and amoxycillin showed equally high, satisfactory treatment results, i.e. more than a 90% response. Similarly, there was no statistically significant difference between the treatment groups at the second follow-up visit (about 30 days after start of treatment). Bacteriological cultures from the nasopharynx showed equal distribution of Haemophilus influenzae, Branhamella catarrhalis and Streptococcus pneumoniae between the study groups. Elimination of the initially occurring pathogens was equal in the two study groups with the exception of B. catarrhalis which was eliminated to a significantly higher extent with amoxycillin/clavulanate. Both drugs were well tolerated. In patients with recurrent otitis media or therapeutic failure, treatment with amoxycillin/clavulanate for 7 days results in high, satisfactory clinical effects and is comparable to treatment with amoxycillin for 10 days.