The aims of this study were to detect BRO beta-lactamase types and to evaluate any correlation with the susceptibility patterns of 90 clinical isolates of Moraxella catarrhalis. The overall prevalences of the bro-1 and bro-2 genes were 78% and 12%, respectively. Penicillin G MICs for BRO-1(+) isolates were significantly higher than those for BRO-2(+) isolates. All the isolates were susceptible to amoxycillin-clavulanate, levofloxacin and cefixime. Resistance to clarithromycin, tetracycline and trimethoprim-sulphamethoxazole was 1.1%, 2.2% and 1.1%, respectively. One-step, length-based PCR was an efficient method to screen for BRO beta-lactamase genes.