Bacteria in different portions of the middle ear were studied in 68 patients with otitis media purulenta chronica (OMPC) as well as sensitivity of the bacteria to different antibacterial medicines. Microflora was followed up for a months after surgical treatment. Prevalent were Staphylococcus aureus and gram-negative flora most sensitive to defended penicillines, cephalosporins of the third generation and fluoroquinolones. Destructive changes in the temporal bone, acoustic and vestibular functions by type of the causative agent were examined.