Abstract:The issue of adequate assessment of socio-economic and ecological sustainability of divers agricultural holdings is among most topical academic and practical problems. It is particularly important for smallholder farms accounting for the majority of all farms in the globe.In Bulgaria unregistered farms of Natural Persons account for almost 98% of all farms in the country, cultivate a third of all farmlands, graze 85% of cows, 90% of sheep, and around a third of pigs, and employ almost 93% of workforce in the sectors. This article applies a holistic framework and assesses sustainability of farms of Natural Persons in Bulgaria during current stage of EU CAP implementation. Initially a new governance aspect of farm sustainability is justified and method outlined. After that assessment is made of integral, governance, economic, social, environmental sustainability of farms of Natural Persons of different size, specialization, and location, and comparative sustainability to other type of farms. Finally, directions for further research and amelioration of sustainability assessment practices are suggested. Overall sustainability of Natural Persons in the country is at a good level, with superior levels for environmental and social sustainability, close to the low level governance sustainability, and inferior economic sustainability. Comparative sustainability of holdings is lower than other juridical type. There are great variations in sustainability levels of farms of different kind and location. Share of Natural Persons with good and high sustainability is smaller than other categories of farms and majority of Natural Persons have no comparative advantages in terms of sustainability, and in a middle term will cease to exist.