Eighty isolates of Shigella spp. (37 Shigella flexneri and 43 Shigella sonnei) from patients with travellers' diarrhoea were studied. Susceptibility tests revealed high levels of resistance, especially to ampicillin (65%), tetracycline (78%) and trimethoprim (75%), and particularly among the S. flexneri isolates. Dihydrofolate reductase 1 genes (dfrA1) were prevalent among the trimethoprim-resistant isolates, while oxa genes predominated among the ampicillin-resistant isolates. Chloramphenicol resistance was associated with production of chloramphenicol acetyltransferase, while nalidixic acid-resistant isolates had a single mutation in the gyrA gene. The results indicate a continuing need for resistance surveillance and rational use of antimicrobial agents.