As part of Well Integrity Programs Materials Selection has become a critical issue regarding fitness for service assurance and risk management. In the last few years Pan American Energy Integrity Division directed its efforts towards the implementation of combined methods for materials selection of well components involving advanced process simulation erosion-corrosion modeling and fitness for service assessment. Specific objectives of this project were the following: To provide a solid platform required to address erosion and corrosion mechanisms affecting both carbon steel low alloy steels and stainless steels used as manufacturing materials for tubular and well head components. To predict metal loss rates and fitness for service evolution due to changes in operating and fluid conditions. To develop a framework required for materials selection and integrity assurance programs involving inspection monitoring mitigation and maintenance. As a result of this project the following developments were possible: Well materials investment reduction. Increase in production rates without sensible risk increment. Accurate residual life estimates. Performance improvement of corrosion and erosion mitigation and monitoring programs. Enlargement of the gas wells materials framework.