During July 1995, an outbreak of Salmonella typhimurium definitive type (DT) 170, an unusual strain, occurred in South Wales. A case-control study found that illness was associated with eating kebabs (odds ratio undefined, P=0·002), doner kebabs (odds ratio 7·9, 95% confidence interval 1·5–20·5, P=0·02) and kebabs with yoghurt based relish (odds ratio undefined, P=0·009) but not with eating kebabs with mayonnaise-based relish (odds ratio 2·4, 95% confidence interval 0·4–13·9, P=0·53). Environmental investigations discovered a complex web of producers and wholesale suppliers. Kebab meat and yoghurt had been supplied to the two main implicated outlets by a single wholesaler. Samples of raw minced lamb and several environmental swabs taken at the wholesaler were positive for S. typhimurium DT170. Blood- stained, unsealed yoghurt pots were observed to be stored under a rack of raw lamb. Investigators of food poisoning outbreaks linked to takeaway food should consider cross- contaminated relishes and dressings as well as undercooked meat as potential vehicles of infection.