The susceptibilities of 200 clinical isolates of the Bacteroides fragilis group to 11 antimicrobial agents were determined by the broth microdilution method of the National Committee for Clinical Laboratory Standards. All isolates were susceptible to imipenem and ticarcillin-clavulanic acid. The rates of resistance to cefoxitin and clindamycin were low (4 and 6%, respectively), while those to ceftizoxime and cefotetan were higher (10.5 and 24%, respectively).