In the United States, 50% of beginning teachers leave the classroom in their first 5 years of teaching (Ingersoll & Smith, 2004). This study evaluated the psychometric properties of the Perceptions of Success Inventory for Beginning Teachers (PSI-BT), an instrument that can be used to make informed decisions for improving induction programs and ultimately to retain beginning teachers. The PSI-BT assessed factors that contribute to beginning teachers' perceptions of success as well as beginning teacher retention. An extensive literature review, expert opinions, and confirmatory factor analysis established the construct validity of the PSI-BT. Structural equation modeling analyses determined the factors that predicted beginning teacher satisfaction, commitment, retention intentions, and retention. When used to inform targeted professional development and support, we believe this instrument can help school districts improve retention and effectiveness of beginning teachers. (Contains 4 notes, 3 tables, and 5 figures.)