This volume constitutes the refereed proceedings of the 6th International Workshop on Grid Economics and Business Models, GECON 2009, held in Delft, The Netherlands, August 2009. The 8 full papers included in this volume were carefully selected from 25 submissions. They aim at presenting current results and innovative research in the area of Grid economics. The papers are organized in topical sections on market models and mechanisms, business support tools and business-related resource allocation. The proceedings are rounded off by 6 papers on research-in-progress which were selected from many paper submissions. These papers provide an overview about ongoing research projects on Grid and Cloud economics, addressing economic-related research in Cloud computing and software services.