This paper is a case study of the data quality program implemented for Galaxy, a large health care data warehouse owned by UnitedHealth Group and operated by Ingenix. The paper presents an overview of the program’s goals and components. It focuses on the program’s metrics and includes examples of the practical application of statistical process control (SPC) for measuring and reporting on data quality. These measurements pertain directly to the quality of the data and have implications for the wider question of information quality. The paper provides examples of specific measures, the benefits gained in applying them in a data warehouse setting, and lessons learned in the process of implementing and evolving the program.