The main aim of this paper was an attempt to describe the issue of co-existence in the context of the development of the bioeconomy. An additional aim was to identify categories of costs of coexistence and their size in the situation of parallel production ie. organic and conventional that takes place in farms certified as organic. The study was based on data collected for 2015 from 28 organic farms from Mazovia province. It was found that co-existence as an economic institution allows to ensure for individuals and social groups the freedom of choice and build confidence among them for the integrity and quality of products coming from different production and distribution systems. Thus, given the importance of standards for food safety and quality the coexistence plays a special role in the development of the agro-food chains and distribution of food and feed. In the studied organic farms parallel production can be carried out by implementing proper practices of coexistence, allowing to optimize the organization and economics of their activities. The coexistence costs were related mainly to isolation and segregation and amounted to ca. 4,66% of all costs.