During an Integrated Quality Control (IQC) project for finishing pigs, the application of veterinary drugs was registered by means of a logbook on 75 pig finishing farms. Investigated is as to how far the application of veterinary drugs to animals is linked up with clinical observations, management and climatic conditions on the farm and to what extent the application of veterinary drugs is linked up with the occurrence of pathological findings in pigs at the slaughterhouse. The results indicate that more veterinary drugs are used as there are more clinical findings on a pig farm. This is particularly true for the autumn-winter period. Farms that use more veterinary drugs have a higher percentage of pigs with pathological findings at the slaughterhouse. As the point of time of treatment of respiratory disorders is closer to the slaughter date, there is a higher percentage of pigs suffering from pneumonia at the slaughterhouse. Farms treating pigs in the first thirty days of the finishing period against intestinal disorders have a distinct higher percentage of pigs suffering from pneumonia at the slaughterhouse. It appears that less veterinary drugs are used at farms having specific housing and management characteristics.