Three hundred seventy five isolates of Streptococcus pneumoniae were collected from 14 medical institutions in the Kinki region of Japan between November 2003 and February 2004. We determined the minimum inhibitory concentration (MIC) of penicillin G (PCG) and 25 of other antimicrobial agents against these isolates according to the National Committee for Clinical Laboratory Standards (NCCLS). Overall, 71.5% of all isolates were resistant to PCG (intermediate and resistant categories were 51.7% and 19.8%, respectively). For the carbapenems and penem, the rank order of activity was PAPM (MIC90, 0.12 microg/ml) > IPM (0.25 microg/ml) > MEPM (0.5 microg/ml) = FRPM (0.5 microg/ml). For the cephems, the overall rank order of activity was CPR (MIC90, 0.5 microg/ml) = CDTR (0.5 microg/ml) > CTRX (1 microg/ml) = CTX (1 microg/ml) = CZOP (1 microg/ml) = CFPN (1 microg/ml). Rank order activity for six of fluoroquinolones was TFLX = MFLX (MIC90, 0.25 microg/ml) > GFLX (0.5 microg/ ml) = SPFX (0.5 microg/ml) > LVFX (1 microg/ml) > PZFX (4 microg/ml). The rate of resistance to fluoroquinolones per the NCCLS criteria were very low, ranging from 0.7% to 2.6%. Rate of resistance to other antimicrobiotics were CAM, 77.0%; CLDM, 41.7%; TEL, 0%; VCM, 0%; ST, 32.7%, and CP, 21.4%.