The following technical report is available from http://aib.informatik.rwth-aachen.de/: Delia Kesner, Femke van Raamsdonk, Joe Wells (eds.) HOR 2004 -- 2nd International Workshop on Higher-Order Rewriting 2004-03 This report contains the proceedings of the 2nd International Workshop on Higher-Order Rewriting (HOR 2004), which was held on June 2, 2004 as part of the Federated Conference on Rewriting, Deduction, and Programming (RDP 2004) in Aachen, Germany.