The Eighth Italian Conference on Theoretical Computer Science (ICTCS 2003) was held at the University Residential Center of Bertinoro, Italy, on October 13-15 2003. The center is composed of three large historical and monumental buildings not far from one another, forming a united complex on the top of the built up area of the ancient town of Bertinoro. Previous conferences took place in Pisa (1972), Mantova (1974 and 1989), L'Aquila (1992), Ravello (1995), Prato (1998), and Torino (2001). The conference aims at bringing together computer scientists, expecially youngresearchers, tofostercooperationandexchangeideasandresults.Itsmain topicsinclude: analysisanddesignofalgorithms, datatypesanddatastructures, theory of logical design and layout, computability, complexity, automata, s- bolic and algebraic computation, security, cryptography, speci?cation and ve- ?cation, formal languages, foundations of functional programming, foundations of logic programming, term-rewriting, semantics, type theory, new computing paradigms, parallel and distributed computation, theory of concurrency, theory of databases, theory of knowledge bases, theory of robotics. The program committee, consisting of 14 members, considered 65 papers and selected 27 for presentation. These papers were selected on the basis of origin- ity, quality, and relevance to theoretical computer science. These proceedings include the revised versions of the 27 accepted papers and the invited talks by Marios Mavronicolas (Extreme Nash Equilibria), Martin Hofmann (Certi?cation of Memory Usage), and G erard Boudol (On Programming Models for Mobility)."