This paper applies the interdisciplinary New Institutional Economics framework, identifies diverse market, private, collective, public and hybrid modes of governance and assesses their impact on agrarian sustainability in Bulgaria. First, the methodological framework of the study is outlined. After that dominating governing modes in Bulgarian farms of different juridical type, size, specialization, ecological and geographical location are identified, and their impacts on agrarian sustainability and its economic, social, and environmental pillars evaluated. In conclusion implications for further research, public policy improvement, and private managerial strategy formation are presented. Agricultural producers of different type use quite unl...