Over the last few years major attempts have been made to transform small and mediumsized enterprises (SMEs) into more sustainable companies. In essence, these attempts aim at improving the organisational and technical capabilities of companies. Whereas larger companies have been able to appropriate the concept of pollution prevention, in many cases SMEs lack the resources to develop this new capability. SMEs may have to rely on the initiatives, knowledge and capacities of other actors. This paper reviews whether partnerships can overcome the deficiencies of SMEs by analysing the results of a decade of promotion of pollution prevention in the Netherlands. We focus on two issues. First, we evaluate the effects of partnership networks for the promotion of pollution prevention in SMEs. Second, we analyse the different roles partners can play within such networks. We conclude that most pollution prevention projects succeed in realising environmental improvements for the participating companies, but for the majority it is a one-time experience. Not much is learned about the art of pollution prevention itself. Another problem is that current partnerships are not able to involve more defensive companies through voluntary pollution prevention projects.