These volumes comprise the Proceedings of the Ninth International Symposium on Landslides, held in Rio de Janeiro, Brazil, from June 28 to July 2, 2004. Information on the latest developments in Landslide Studies is presented by invited lecture reports, specialized panel contributions and over two hundred and forty technical papers, grouped in the following themes: - Mapping and geological models in landslide hazard assessment, - Advances in rock and mine slopes design, - Field instrumentation and laboratory investigations, - Pre-failure mechanics of landslides in soil and rock, - Mechanisms of slow active landslides, - Post-failure mechanics of landslides, - Stabilization methods and risk reduction measures. A wealth of the latest information on all aspects of landslide hazard, encompassing geological modelling and soil and rock mechanics, landslide processes, causes and effects, and damage avoidance and limitation strategies.