This text constitutes the refereed proceedings of the 19th Annual Symposium on Theoretical Aspects of Computer Science, STACS 2002, held in Antibes - Juan les Pins, France, in March 2002. The 50 revised full papers presented together with three invited papers were carefully reviewed and selected from a total of 209 submissions. The book offers topical sections on algorithms, current challenges, computational and structural complexity, automata and formal languages, and logic in computer science.