An outbreak of paratyphoid fever due to Salmonella paratyphi A occurred during June 1991 to March 1992 in Duliajan, Assam. S paratyphi A was isolated from blood, stool, urine and gall bladder content. Most of the strains (92%) were resistant to ampicillin and a few (10%) to chloramphenicol. Most of the strains belonged to phage type I.