This book constitutes the refereed proceedings of the 10th International Conference on Logic Programming, Artificial Intelligence, and Reasoning, LPAR 2003, held in Almaty, Kazakhstan in September 2003. The 27 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 65 submissions. The papers address all current issues in logic programming, automated reasoning, and AI logics in particular description logics, proof theory, logic calculi, formal verification, model theory, game theory, automata, proof search, constraint systems, model checking, and proof construction.