Approximately 5 years ago a task analysis was conducted by the Certification Board of Infection Control (CBIC) to describe infection control practice. This task analysis served as the basis for development of the certification examination. This article describes the process used to update and revalidate the original task analysis to ensure the continued validity and job relatedness of the certification process. Using a modified Delphi technique, several panels of representative expert infection control practitioners (ICPs), a total of 29 persons, participated in an iterative process to define the practice dimensions of infection control and to link these practice dimensions to the certification examination. In general, there was a high level of congruence between respondents on the original task analysis and the expert panels, although a few differences in practice were identified among ICPs in extended care facilities and a few new tasks were identified. In addition, a revised content outline for the examination was created by placing clusters of knowledge statements together around common themes.