Community college completion rates have remained stagnate over the past decade; therefore, college leaders and policy makers continue to seek institutional factors that positively affect graduation rates. The purpose of this study was to determine the effectiveness of Phi Theta Kappa Honor Society (PTKHS), the nation’s largest and oldest honor society for community college students. The completion rates of PTKHS members and rates of other students were investigated using simple statistical procedures for determining significance of differences in proportions. Data sources included published data from the National Center for Education Statistics Integrated Postsecondary Education Data System surveys, the National Student Clearinghouse, and Beginning Postsecondary Student Longitudinal Study. Results indicate completion gaps between PTKHS and other community college students were substantially high, so much so in fact, that tests of significance were not needed to assist the audience of this research in determining the definite impact of PTKHS on student success.