Heavy industrial region still continuing its redeployment, Wallonia (Belgium) has initiated and support the creation and the development of clusters since 2001. Facing the lack of leading sectors or enterprises, the approach adopted is resolutely bottom-up :the initiative of a cluster’s creation must come from the enterprises themselves (mainly SME’s) wishing to collaborate in a network targeting at one (or more) market(s). Five years of experimentation later, there is in Wallonia 10 clusters involving 647 enterprises and 143 support organisations (R&D centres, universities, training centres). We can list 59 current partnerships amongst firms (R&D, development of a product, joint commercial moves, ) involving 222 enterprises and research centres. Some companies has been created (EIG, spin-off, ) as a result from these clusters. After a first stage of development, the walloon clusters launched in 2001/2003 extend their action to international field. After a brief overview of the main theories related to the cluster concept, the paper is exploring the first results (qualitative and quantitative) of the experimental phase of this clustering policy implemented by the Walloon Region, a.o. on the basis of the MERIT (University of Maastricht, NL) external evaluation written in March 2004. The conclusions and recommendations of this study have largely inspired the redaction of a regional Decree concerning the support and the development of the Walloon clusters (to be adopted by the regional Parliament at the end of 2006). ; info:eu-repo/semantics/published