Faropenem is a new oral penem with a structure different from current β-lactams including carbapenems. The susceptibility of Streptococcuspneumoniae, Haemophilus influenzae and Moraxella catarrhalis to faropenem, a macrolide, a β-lactam, a β-lactam/β-lactamase inhibitor combination and two fluoroquinolones was investigated. S. pneumoniae was the most susceptible of the three species to faropenem. The MIC90s of faropenem against M. catarrhalis and H. influenzae were 0.5 and 1 mg/l, respectively. They were similar to amoxiclav (MIC 90s of 0.25 and 0.5 mg/l). The quinolones showed strong activity against H. influenzae. A cluster analysis of the activities of amoxycillin and faropenem demonstrated a direct relationship between the two antimicrobial agent's activities and resistance profiles against both S. pneumoniae and H. influenzae.