Purpose: This instrumental case study (Stake, 1995) explores the benefits experienced by mentor teachers who mentored resident teachers in a year-long residency program. Design/methodology/approach: The study was grounded by the Benefits of Being a Mentor conceptual framework, as defined by Ragins and Scandura (1999). The participating mentor teachers engaged in semi-structured interviews and a focus group. The data were analyzed through inductive and deductive data analysis techniques. Findings: Using inductive and deductive data analysis techniques, three themes emerged on the benefits of being a mentor teacher: (1) extra support in the classroom, (2) professional learning and growth opportunities, and (3) investing in the future of education. The teachers' perceived benefits were related to the connectedness of their personal and professional growth, the growth of the resident teachers and their students' learning. Originality/value: Mentor teachers play a vital role in teacher residency programs, as they are the primary influence on their resident teachers' pedagogical praxis. In a residency program, mentor teachers support resident teachers' sustained teaching experience by hosting them for one full academic year in their classrooms; therefore, exploring the benefits they receive from serving in this role is essential.