Tensions can occur in the mentor-mentee relationship during school-based professional experiences that require problem solving. What are the tensions for mentor teachers in preservice teacher education and how might these tensions be resolved? This qualitative study collected data from 31 high school mentor teachers about tensions experienced with preservice teachers during professional experience programmes. Three themes emerged around the causes of tensions (low- to high-level conflicts) within the mentor-mentee relationship, namely: (1) personal issues (i.e. incompatibility, personality differences, language); (2) pedagogical issues (i.e. lack of pedagogical and content knowledge, differences in teaching styles); and (3) professional issues. Strategies to resolve these tensions include: maintaining a positive professional relationship, regular feedback as a way to address issues, sharing responsibility and empowerment, and using empathy for specific situations. As a theoretical contribution, this study provides a model around low- and high-level conflict associated with personal, pedagogical and professional (3Ps) issues. The study focused on mentors only and further research is required about the tensions preservice teachers experience with their mentors and ways in which these tensions can be resolved.