A decision was made to get to know the degree of Salmonella spp. spread in slaughter chickens in selected points of the slaughter and after-slaughter dressing line in poultry plants. Slaughter chickens came from the north-east part of Poland. They were delivered from the place of origin for slaughter on the same day. The examinations were carried out in quarters I, II, III and IV of 1998 from 400 slaughter chickens. All the birds were admitted healthy by the Veterinary Inspection. Swabs were taken from chickens at the following points of the slaughter and after-slaughter dressing line: from the cloaca after stunning - they were taken with a sterile faeces glass rod, from the surface of the skin and body cavities of whole birds after evisceration, from whole birds after washing, but before putting them in the cooler, and from whole birds after the end of cooling, in the whole bird continuous cooling plant at the end of the production day. The investigation results obtained at isolating Salmonella spp. from poultry on the slaughter and after-slaughter dressing line, proved that in some of its places bacteria were found more often than in others. In slaughter chickens, Salmonella spp. occurrence was found after stunning in 8%, after evisceration in 28%, before cooling in 44%, and after cooling in 20%. The lowest Salmonella spp. contamination rate in slaughter birds was found in the case of chickens after stunning, while the highest before cooling. Salmonella spp. were isolated in chickens most often in quarter II and III. The following serological types of Salmonella spp. were isolated from whole chickens: S. Enteritidis, S. Typhimurium, S. Saintpaul, S. Agona, S. Infantis.