In 1996 a Committee for antibiotic resistance surveillance in Croatia was founded by the Croatian Academy of Medical Sciences. In this study antibiotic surveillance results for the period June 1-December 31, 1997 from 12 microbiology laboratories throughout Croatia are presented. Sensitivity to antibiotics was determined by disk diffusion method for the following bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus spp., Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa. In general, high proportion of resistant isolates was recorded throughout Croatia, although some regional variations were noticed. Mean resistance of pneumococci to penicillin was 38%, in S. aureus resistance to methicillin was 47%, and 3rd generation cephalosporin-resistance in E. coli was 6% and in Klebsiella spp. 21%. In P. aeruginosa resistance to gentamicin averaged 50%, to imipenem 13% and to ceftazidim 8%. Future aims of the Committee are to continue routine antibiotic resistance surveillance during certain periods every year, and to estimate clinical significance of resistant bacteria, detect mechanisms of resistance and improve the quality of laboratory work through education and quality control projects.