The University of Zambia (UNZA) Mentor Training Program is conducted annually to strengthen the mentorship capacity of postgraduate programs for the health professions. This intensive five-session course trains faculty members in the mentorship of students. Established by senior UNZA leaders and US-based collaborators, this program was designed to address gaps in mentorship identified at the institutional level. Faculty facilitators developed the course curriculum and used a train-the-trainer model to ensure program sustainability. Participants were faculty members who mentor PhD and Master of Medicine students. To assess the program's impact, mentors and their mentees completed questionnaires on the mentor's mentoring competencies at the end of the course and 1 year later. Competency scores were compared longitudinally to quantify potential changes in mentoring behaviors. Mentors and mentees alike noted mentor growth in all competency domains from postcourse to 1 year later, providing evidence of a trend toward improvement in mentorship and that the program may have sustainable and positive effects on mentoring behaviors over time. Salient areas of growth corresponded to emphasized topics and discussions, including addressing diversity, aligning expectations, assessing capacities, motivating mentees, and fostering independence. These findings suggest that mentors internalized this content and transferred it to behavior change. The behavior changes may reveal a larger change in the institutional environment around the mentoring of students. The UNZA Mentor Training Program appears to have sustained impact after a year and should bode well for future benefits to students, faculty, and the institution.