In order to support the biogas market in Southern and Eastern Europe the BiG>East project “Promoting Biogas in Eastern Europe – Mobilization of Decision Makers and Training for Farmers” was supported by the European Commission under the Intelligent Energy for Europe Programme. The general objective of BiG>East was to promote the production and use of biogas as a secure and sustainable energy source in six target countries of Eastern and Southern Europe: Bulgaria, Croatia, Latvia, Romania, Slovenia, and Greece (BiG>East target countries). The BiG>East project aimed to build capacities and transfer knowledge from project partners of Western Europe with extensive, long-term expertise to farmers, biogas plant operators, and decision makers in Southern and Eastern Europe. This was achieved by the organisation of 13 mobilisation campaigns for decision makers, 19 training courses for farmers and several study tours. Show cases were elaborated to support the mobilisation campaigns, and training material (biogas handbooks) was prepared for the training courses. The present paper shows the experiences and lessons learnt during the implementation of the 30 month BiG>East project.