This volume contains the Proceedings of the IABEM International Sym- posium on Boundary I~ntegrall Methods for Nonlinear Problems, held at the Certosa di Pontignano near Siena (Italy) on May 28 - June 3, 1995. The Symposium was sponsored by IABEM (International Association for Boundary Element Methods) and co-sponsored by IUTAM (International Union of Theoretical and Applied Mechanics). The members of the Scientific Committee of the Symposium are Heinz Antes (Germany) Satya N. Atluri (USA) Dimitri E. Beskos (Greece) Thomas Cruse (USA) Massimo Guiggiani (Italy) George C. Hsiao (USA) Shoichi Kobayashi (Japan) Gunther Kuhn (Germany) Vladimir G. Maz'ya (Sweden) Luigi Morino (Italy, co-organizer) Renzo Piva (Italy) Wolfgang L. Wendland (Germany, co-organizer) Pieter J. Zandbergen (The Netherlands) Franz Ziegler ( Austria, IUTAM representative) The contributions include mathematical issues on boundary integral equa- tions and boundary element methods as well as applications to fluid and solid mechanics and to heat transfer. The individual contributions are briefly reviewed in the following.