Spread of plant disease in production chains of planting material is a process of great economic importance, but has received little attention from plant disease epidemiologists. Disease control in production chains is therefore often based on rules of thumb and expert judgement by regulatory bodies, rather than on an explicit analysis and evaluation of the epidemiological and economic consequences of alternative strategies. This paper puts forward the idea that individual-based models may be used as a framework to simulate the spread of disease-causing organisms in plant production chains. The ¿individuals¿ in this context are the trading units (e.g., batches, lots) of a production chain. The quarantine disease ¿potato brown rot¿, caused by the bacterium Ralstonia solanacearum, is used as an illustrative example. The model simulates the spread of potato brown rot over all potato growing farms and fields in the Netherlands over a chosen time frame. It addresses the relevant infection pathways for this disease in potato production and is spatially explicit.