Throughout a period of thirteen years (from 1965 to 1977 inclusive), samples of scrapings from meat vans were examined weekly for the presence of Salmonella. Samples were collected from the vans on the precincts of the public slaughter-house in Groningen. Of the total number of 6,751 samples studied, 213 (3.16 per cent) were positive for the presence of Salmonella. During the period from 1965 to 1970, the proportions of contaminated samples gradually decreased from 4.85 to 1.11 per cent, whereas it increased again up to 6.33 per cent in 1976. There was a limited seasonal effect on contamination of the scrapings with Salmonella, the highest rates of contamination being recorded during the period from May to October inclusive (warm and humid season). The serotypes most frequently isolated on examination were S. typhi-murium, S. brandenburg and S. panama. These serotypes were also constantly found to be present in other material such as samples of minced meat and scrapings from slaughter-house and butcher's shops. It is concluded that contaminated meat vans are a factor in maintaining cycles of contamination by Salmonella organisms in a rather large area.