The University of Bologna First Summer School on "Aspects of Organizational Complexity" offers an intensive 10-day introduction to the dynamics of complex systems in the computer, natural and social sciences. Examples of the complex systems that will be examined include computer networks (such as the internet), textual networks (such as those emerging from the co-occurrence of words contained in media reports), biological systems (such as ant colonies), markets (such as the stock exchange), business organizations, and social systems defined at various scales. The program will stress the distributed nature of decision and communication processes that imply storage, processing and retrieval of information.