This book constitutes the proceedings of the 19th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2013, held in Rome, Italy, in March 2013. The 42 papers presented in this volume were carefully reviewed and selected from 172 submissions. They are organized in topical sections named: Markov chains; termination; SAT/SMT; games and synthesis; process algebra; pushdown; runtime verification and model checking; concurrency; learning and abduction; timed automata; security and access control; frontiers (graphics and quantum); functional programs and types; tool demonstrations; explicit-state model checking; Buchi automata; and competition on software verification.