At the heart of Multi-Paradigm Modeling (MPM) is the conviction that modeling "everything" explicitly, at the right level of abstraction and using the most appropriate formalism( s) is the key to success in model driven engineering. Indeed, the model based design of complex systems requires the use of multiple modeling languages to cope with the inherent heterogeneity of such systems, to offer different points of view on all their relevant aspects, to cover the different activities of the design cycle and to allow reasoning at different levels of detail during the design process. However, essential questions need to be answered in this context: Those of the coupling, the combination, the composition, the transformation and the integration of models and of modeling formalisms. The aim of the Workshop on Multi-Paradigm Modeling is to provide a forum for both researchers and practitioners to share on the theories, methods and technologies that address the specific set of challenges of the MPM domain. The sixth edition of theWorkshop on Multi-Paradigm Modeling (MPM'12) was held this year in Innsbruck, Austria, organized as a satellite event of MODELS. In this paper we summarize the results of this year's event.