Identification of critical points for contamination of feed and spread of Salmonella may contribute to the development of control plans. A cross-sectional study was conducted to identify Salmonella clonal groups in feed mill facilities. A total of 1,322 samples were collected in four swine feed manufacturing facilities. Samples were taken from ingredients and from dust deposited on the floor and on the inner surface of storage bins, bucket elevators, mills, mixers, scales, pelleting chamber and cooler.