Forest owner association (FOAʼs) in Slovenia and in German federal state of Baden-Württemberg have been analysed in terms of efficient fulfilment of assignments written in their statutes. Furthermore, the purpose of the research was to present FOAʼs in both countries in more detail, as well as to display FOAʼs fundamental elements (e.g. FOAʼs size, number of performed activities) in the light of collective action. FOAʼs efficiency has been analysed using non-parametric method ŽData Envelopment AnalysisŽ (DEA). Using selected inputs and outputs, two models have been developed for each country, reflecting technical-economic and socio-educational aspects of FOAʼs operation. In addition, another model has been developed combining FOAʼs from both countries and considering all aspects of FOAʼs operation. It was found, that FOAʼs in both countries are on average more efficiently engaged in activities aimed to improve socio-educational aspects. Efficient operation of FOAʼs is a result of rational and personal membersʼ motives, which have been indicated with achieved higher average efficiency of Slovenian FOAʼs comprising more members and more activities, and German FOAʼs comprising fewer members and more activities, respectively. The practical usefulness of this study lies in the calculated target values and lambda weights, thus decision-makers in FOAʼs (e.g. steering committee) have a real potential of improving FOAʼs efficiency by considering target values and/or "imitating" thebest units.