Computational modeling of materials behavior by multiscale materials modeling (MMM) approaches is becoming a reliable tool to underpin scientific investigations and to complement traditional theoretical and experimental approaches of component assessment. At transitional (or microstructure) scales continuum approaches begin to break down and atomistic methods reach inherent limitations in time and length scale. Transitional theoretical frameworks and modeling techniques are developed to bridge the gap between the different length scales. Industrial success in high technology fields relies on the possibility to specifically engineer materials and products with improved performance. The success factor is the ability to make these material related developments timely at relatively low-costs. This demands not only the rapid development of new or improved processing techniques but also better understanding and control of material chemistry, processing, structure, performance, durability, and their relationships. This scenario usually involves multiple length (space) & time scales and multiple processing & performance stages, which are usually only accessible via multi-scale / multi-stage modeling or simulation. In high-payoff, high-risk technologies such as the design of large structures in the aerospace and nuclear industries, the effects of aging and environment on failure mechanisms cannot be left to conservative approaches. Increasing efforts are now focused on developing MMM approaches to develop new material systems (components and devices). Appropriate validation experiments are crucial to verify that the models predict the correct behavior at each length scale. Thus, one of the advantages of these MMM approaches is that, at each scale, physically meaningful parameters are predicted and used in models for subsequent scales, avoiding the use of empiricism and fitting parameters. Recent interest in nanotechnology is challenging the scientific community to design nanometer to micrometer size devices for applications in new generations of computers, electronics, photonics or drug delivery systems. These new application areas of multiscale materials modeling require novel and sophisticated science-based approaches for design and performance evaluation. Theory and modeling are playing an increasing role to reduce development costs and manufacturing times. With the sustained progress in computational power and MMM methodologies, new materials and new functionalities are increasingly more likely to be discovered by MMM approaches than by traditional trial and error approach. This is part of a paradigm shift in modeling, away from reproducing known properties of known materials towards simulating the behavior of hypothetical composites as a forerunner to finding real materials with these novel properties. The MMM 2006 conference provides an international forum for the scientific advances of multiscale modeling methodologies and their applications.