This paper presents a typology of multi-organizational structures that emerge from the interaction of several organizations or are deliberatively created by them. Common in political, military, and business worlds, these inter-organizational partnerships create compositional structures which are controlled by several organizations. Multi-organizational structures offer a very interesting framework for the study of the costs and advantages of cooperation. It is shown that these structures can be characterized in terms of three features, which are purpose of partnership, control and cooperation structure, and dynamics of membership. Implications of each organizational structure on its autonomy and performance are discussed.