This volume contains the papers presented at the 19th International Conference on Automated Deduction (CADE-19) held 28 July-2 August 2003 in Miami Beach, Florida, USA. They are divided into the following categories: – 4 contributions by invited speakers: one full paper and three short abstracts; – 29 accepted technical papers; – 7 descriptions of automated reasoning systems. These proceedings also contain a short description of the automated theor- proving system competition (CASC-19) organized by Geo? Sutcli?e and Chr- tian Suttner. Despite many competing smaller conferences and workshops covering di?- entaspectsofautomateddeduction, CADEisstillthemajorforumfordiscussing new results on all aspects of automated deduction as well as presenting new s- tems and improvements of established systems. In contrast to the previous year, when CADE was one of the conferences participating in the Third Federated Logic Conference (FLo C 2002), and next year, when CADE will be part of the Second International Joint Conference on Automated Reasoning (IJCAR 2004), CADE-19 was organized as a stand-alone event.