The Environmental Council for Cleaner Products in 2000-2001 initiated a collection of experience from the environmental co-operation in 25 product chains. This collection of experience was to elucidate the concrete co-operation between suppliers, enterprises and purchasers, to go through tools and to report on opportunities and barriers for environmental efforts in the entire product chain. This paper aims at giving a comprehensive analysis of the experiences, on the basis of the reporting of the 25 companies and their supply chains (reported by Ettrup and Bauer in 2002. The 25 case studies have been carried out by 4 different consultancy firms for the Danish Environmental Protection Agency, but using different methods and different weighting. The material thus represents a large pool of knowledge, but great caution with its heterogeneity should be taken.