This Proceedings contains the papers presented at the IFAC Workshop on Lagrangian and Hamiltonian Methods for Nonlinear Control, held at Princeton University, USA in March 2000. The workshop featured presentations and in-depth discussions of recent theoretical and practical developments in Lagrangian and Hamiltonian approaches to nonlinear control. New technologies have created engineering problems where successful controller designs must account for nonlinear effects, yet existing theory for general nonlinear systems often proves insufficient. This workshop focused on recent research that gives modeling a central role and focuses on structure that can be exploited in controller design. The research presented covered a diverse set of application areas.