Introduction: Mentorship develops a personal relationship in which a more experienced and knowledgeable person helps a less experienced person. In this study we aimed to investigate the characteristics of an ideal mentor based on the viewpoints of clinical professors of Shiraz Medical School.Materials and Methods: In this descriptive, cross-sectional study, 114 clinical professors of medicine at Shiraz Medical School were investigated using simple random sampling. A valid and reliable questionnaire was used to collect the data .The clinical teachers were asked to express their viewpoints about characteristics of an ideal mentor. A 5 point Likert scale was used for scoring the questionnaire. The statistical analysis was performed through SPSS software, version 16, using both descriptive (frequency, percentage and mean) and inferential (correlation coefficient) statistics.Results: According to the clinical teachers, among the various features, "being provocative" was the most important feature of an ideal clinical Mentor (mean score: 4.67, SD: 0.55).Conclusion: The mentor has a significant role in the professional development of learners. To train teachers as mentors, we can use short-term courses and workshops with emphasis on learning and teaching process, adult learning principles, role clarity, setting educational goals, assessment and evaluation of learner and use of proper feedback.