Can nonprofit boards conduct accurate and trustworthy evaluations of their own performance? Factors that limit trustee self-assessments include problems with available instruments as well as with trustees' critical abilities. Drawing upon previous research that identified six dimensions of board competencies, the author developed and field-tested a new instrument for use in board self-assessments. Information on the reliability and validity of this approach is presented, and implications are drawn for board efforts to monitor and appraise their performance.