Recruiting quality teachers is a top priority for school districts across the country. However, recent research demonstrates that an even greater challenge facing schools is retaining newly recruited teachers, particularly in urban school settings. This article analyzes the effects of two key components of many formal induction programs--mentoring and school-based supports--offered to beginning teachers in Chicago Public Schools. Mentoring is widely accepted as a critical induction strategy, yet this research demonstrates that the provision of "buddy" mentoring is not necessarily sufficient to bring about enhanced retention rates. The findings suggest that mentoring activities that are least often received from new teachers are most strongly correlated with their decisions to remain teaching in the same school. If mentoring activities are going to be an effective means of increasing teacher retention, more attention has to be given to the manner in which mentors are trained to provide "rigorous" mentoring assistance. Whether originating from induction programs or schools, supports beyond mentoring, in the form of teacher collaboration and principal assistance are also strongly correlated with new teachers' intentions to remain in teaching. The strength of school-based supports on beginning teachers' intentions suggests that districts expand induction assistance beyond mentoring to include supports and structures within the schoolhouse to retain their new teachers. (Contains 4 tables and 5 figures.)