The antimicrobial susceptibility of Streptococcus pneumoniae and Haemophilus influenzae isolates during January 2003 to July 2004 was determined to seven various antimicrobial drugs including cefteram (CFTM). The in vitro activities of these drugs against the fresh isolates were compared. The oral cephalosporins including CFTM were potently active against penicillin susceptible S. pneumoniae. The activity of CFTM and cefditoren was the most active among four oral cephalosporins. The susceptibilities of penicillin intermediate S. pneumoniae and penicillin resistant S. pneumoniae to antimicrobial agents were decreased. The MIC of CFTM was not beyond 4 microg/mL for any isolate of S. pneumoniae. The activity of CFTM was very high to beta-lactamase-negative and ampicillin-susceptible H. influenzae isolates. These MIC against all isolates were 0.03 microg/mL or less. The MIC of CFTM was not beyond 1 microg/mL for any isolate of beta-lactamase-positive H. influenzae or beta-lactamase-negative-ampicillin resistant H. influenzae. In conclusion, CFTM exhibits a potent activity against fresh isolates of S. pneumoniae and H. influenzae, and has a potential of effectiveness in the infections.