The antimicrobial sensitivity of Campylobacter jejuni isolated in Bangladesh from patients with diarrhoea, asymptomatic carriers and domestic animals was performed. All isolates were sensitive to erythromycin, gentamicin, furazolidone and kanamycin. Seven percent isolates were resistant to tetracycline, 8% to nalidixic acid, 37% to ampicillin and 100% to sulfamethoxazole-trimethoprim and cephalothin. Tetracycline resistance was observed to be plasmid mediated. No plasmid band(s) coding for ampicillin, sulfamethoxazole-trimethoprim or cephalothin resistance were observed, possibly indicating chromosomally located resistance. No significant differences in the susceptibility patterns of C. jejuni isolated from the different sources was observed. However, 10 patients' isolates showed low molecular weight (2-3, 7 Mdaltons) plasmid band(s) which were completely absent in isolates from asymptomatic carriers and animals.