Salmonella surveillance and control programs arc generally based on results of samples taken from the fattening pigs and intervention measures are limited to the fattening unit. To evaluate the role of the sows in the assignment as Salmonella risk herd we compared the serological status from sows at risk herds to the status of sows at non-risk farms. From this study it is clear that the role of the sows and their serological Salmonella status is a potential influencing factor for the assignment of Salmonella risk farms in the Belgian Salmonella control program, which is principally based on sampling of fattening pigs. More insight in the role of the sow as a reservoir for Salmonella infections might help to define important intervention measures at pre-harvest stage.