A modelling system is presented and used to analyse the impact of milk quota abolishment on Dutch agriculture and economy. The modelling system consists of a regionalised, agri-environmental, partial equilibrium, mathematical programming model of agriculture supply in the Netherlands integrated into a mixed input-output model. It was found that abolition of the milk quota system has large impacts on milk production and livestock numbers and composition. The latter is explained by the strict mineral and manure policies in the Netherlands; an increase in the numbers of dairy cows leaves less room for other livestock. It is also found that, although the total effect on gross value added in the Dutch economy is limited, the effects for individual industries can be large.