Pork represents one major source of human Salmonella infections, but on-farm control strategies for Salmonella contamination are still insufficient. The aim of this study was to localize "hot spots" of Salmonella reservoirs in the course of the fattening period. In a longitudinal study 12 farms with high Salmonella prevalence were examined periodically, starting in the disinfected empty compartment, followed by four subsequent samplings every four weeks. Each sampling comprised faecal and environmental samples, always taken from the same locations, i.e. nipple drinkers, feeders, chains, pen walls (localizations with continuous animal contact), guide boards, passageways, feed tubes, ventilation (localizations without continuous animal contact). Samples were examined by culture and PCR. Overall, 106 out of 1047 samples were culturally Salmonella-positive, resulting in an overall detection rate of 10.1%.