Forty-six Shigella sonnei strains were tested for their susceptibility to seven different antimicrobials. The strains were isolated during an epidemics of shigellosis in Slovenia in 1990. Using the diffusion method, we found that no strain was sensitive to all the antimicrobials tested. The strains differed significantly as concerns their drug sensitivity. The results stressed the necessity of testing each isolated strain for its sensitivity to drugs, before starting any therapy for Shigella sonnei infection.