This paper describes a comparative analysis of human and farm animal salmonellosis in Scotland between 1993 and 1996, with particular reference to Salmonella typhimurium definitive type 104 (DT104). Cattle were the main reservoir, accounting for 73.1 per cent of incidents involving all salmonellae and 69.5 per cent of those involving S typhimurium DT104. The annual rates of incidence in people and cattle were recorded in each Health Board area. Dumfries and Galloway had the highest rate of incidence in cattle for all salmonellae (19.0 per 100,000) but people were affected uniformly across mainland Scotland. However, the rate of incidence of S typhimurium DT104 was highest in Dumfries and Galloway for both people (10.1 per 100,000) and cattle (13.0 per 100,000). In Dumfries and Galloway, Wigtownshire had the highest rates for all salmonellae and for S typhimurium DT104 in both people and cattle. In Dumfries and Galloway, 37.8 per cent of the adult cases of S typhimurium DT104 in people were among those known to have had regular contact with animals, and children under six years of age accounted for 36.3 per cent of the human infections in this region.