The article describes the essence of tri-sector partnership. The subjects of the analysis relate to the models of cooperation between sectors such as: public, private, non-governmental organizations and its legal, economical and social backgrounds (conditionings), which have an influence on thei functioning. Author devotes particular attention, to the analysis of benefits and threats, which are caused by tri-sector cooperation. What is more, author focuses on the influence of developmental factors and barriers on mentioned partnership, which have a great impact on its final results.