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 (FLoC 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.