This article reports on perceptions of the effectiveness of nonprofit organization boards of directors and changes in governance behavior obtained from the first 1,446 users of a free online board performance self-assessment tool known as the Board Check-Up (www.boardcheckup.com), Board Effectiveness Survey Application (BESA). Respondents came from 122 organizations in Canada, the United States, ... [Show full abstract] Australia, and other countries. The article describes the conceptual framework for the study and the underlying theory of change on which it is based. It presents findings on the types of governance issues respondents perceived as most problematic in their boards. It also describes changes in governance behavior and practices reported by respondents, who completed an impact assessment some time after the use of the online self-assessment tool. The results provide empirical support for the value of utilizing the online board performance self-assessment application and insights into its impact as a means of making changes in the governance process. Next steps in this international longitudinal research study are discussed.