The most frequently isolated organism in chronic suppurative otitis media (CSOM) is Pseudomonas aeruginosa. Ototopical ciprofloxacin has proven effectiveness against P. aeruginosa. The purpose of this study is to evaluate the patients with recurrent otorrhoea caused by CSOM that was unresponsive to topical ciprofloxacin. Eighty-eight patients (18-77 years of age) with otorrhoea due to CSOM were reviewed retrospectively. All of them were initially treated with ciprofloxacin eardrops but the otorrhoea failed to resolve. Bacteriological specimens were processed and identified with standard cultures. In vitro antimicrobial susceptibility of these bacterial isolates was assessed by an agar disc diffusion method. Isolates were tested against 16 antibiotics. Ciprofloxacin-resistant P. aeruginosa were isolated in all cases. Imipenem was the most sensitive antibiotic agent with an overall susceptibility rate of 96.5%, followed by amikacin (55.6%), piperacillin/tazobactam (37.5%) and ceftazidime (31.8%). In our series, ciprofloxacin-resistant P. aeruginosa is increasing recently. Continuous surveillance is necessary to monitor antimicrobial resistance and to guide antibacterial therapy.