Although an increasing number of studies have examined students' participation in undergraduate research (UR), little is known about faculty perceptions of mentoring in this context. The purpose of this exploratory study was to investigate four aspects of mentoring UR, including how faculty define high-quality UR mentoring and operationalize it in practice; what the perceived benefits and challenges of UR participation are for mentors and students; how mentoring relates to faculty perceptions of their other roles (teachers, advisors, and scholars); and how participation in various communities of practice influences UR mentoring. Sixty faculty respondents at a private, midsized comprehensive institution completed an online survey. In a series of qualitative analyses, responses to open-ended questions were coded as instrumental, psychosocial, or blended. Analyses revealed that faculty perceptions of UR mentoring were impacted by faculty approach to UR mentoring and faculty rank. These findings may be helpful in the development of UR programs and faculty support programming.