Summary Between 1st january 1992 and 15 april 1993, we send 664 samples of pus from cases of otitis media to the Microbiology Laboratory of the Trousseau Hospital. Of these, 491 gave positive results, (352 bacteries) while the remaining 26,1 % were negative (i.e. sterile) when cultivated. The main bacteria were : Haemophilus influenzae 48 % (28 % ß-lactamase+), Streptococcus pneumoniae 30 % (14 % sensitive to Penicillin), Pseudomonas aeruginosa 7 %, Staphylococcus aureus 9 %. 104 pneumococci were isolated (30 % of the micro organisms found), of which 54 exhibited decreased sensitivity to Penicillin, i.e. 52 % of the pneumococci isolated. The MIC of 47 of these pneumococci exceeded 1mg/l and they were therefore resistant to Penicillin G (45 %). As E.N.T. specialists, our concern was to evaluate the extent of pneumococci resistance (MIC > 1mg/l) in relation to the characteristics of the otitis examinated, whether initial acute otitis media, relapsing acute otitis media, or lingering otitis. In these diseases, the percentage of resistant pneumococci (MIC > 1 mg) showed a regular increase as the number of relapses and then the chronicity of the otitis increased, such that 50 % of the pneumococci isolated during the 1st trimester of 1993 were resistant. The therapeutic approach adopted in our Department is to increase the dosage of Amoxicillin (150 mg/kg/d) and combine it with Rifampin (20 mg/kg/d) during initial treatment.