Risk-based ranking is a procedure that ranks active substances according to their potential environmental risk, which can be used to prioritise effort in environmental risk assessment procedures. An important aspect in this procedure is the extent of use of the active substance. However, use volume data for veterinary pharmaceuticals are generally not publicly available. Therefore, the use of several groups of pharmaceuticals was estimated. For this, available data were collected from different sources and used to calculate the average use, related with the total meat production in the respective countries. Then, an extrapolation, based on food-stuff production data, yields a rough estimate of the use volume for all European countries, largely based on 2004 data. The estimated use was 5393 tons antibiotics, 194 tons antiparasitics and 4.6 tons hormones, 221 tons to treat the alimentary tract and metabolism related disorders, 120 tons CNS active substances, 60 tons of substances used for blood and blood forming organs and 52 tons for muscles and skeleton related disorders. In total, an estimated 6051 tons of active substances in veterinary medicines were used in the European Union. We discuss available data sources and quality, our method and possible refinement of our approach. Environmental risk-based ranking procedures of veterinary substances would benefit from more detailed use data.