This book constitutes the refereed proceedings of the First International Conference on Theory and Practice of Model Transformations, ICMT 2008, held in Zurich, Switzerland, in July 2008.

The 17 revised full papers presented were carefully reviewed and selected from 54 submissions. The scope of the contributions ranges from theoretical and methodological topics to implementation issues and applications. The papers include different issues related with: process and engineering of model transformations; model transformations supporting concurrency and time; matching and mapping within model transformation rules; language support for model transformation reuse and modularity; and correctness and analysis of model transformations.