OBJECTIVE : The Spanish Society for Medical Oncology (SEOM, for its acronym in Spanish) and the National Commission for the Specialty of Medical Oncology seek to highlight the important workload and unrecognized dedication entailed in working as a Medical Oncology (MO) resident mentor, as well as its relevance for the quality of teaching units and the future of the specialty. METHODS : The current situation and opinion regarding the activity of MO resident mentors was analyzed by reviewing the standing national and autonomic community regulations and via an online survey targeting mentors, residents, and physicians who are not MO mentors. The project was supervised by a specially designated group that agreed on a proposal containing recommendations for improvement. RESULTS : Of the MO mentors, 90% stated that they did not have enough time to perform their mentoring duties. An estimated 172 h/year on average was dedicated to mentoring, which represents 10.1% of the total time. MO mentors dedicate an average of 6.9 h/month to these duties outside their workday. Forty-five percent of the mentors feel that their role is scantly recognized, if at all. CONCLUSIONS : The study reveals the substantial dedication and growing complexity of MO resident mentoring. A series of recommendations are issued to improve the conditions in which it is carried out, including the design of systems that adapt to the professional activity in those departments that have time set aside for mentoring tasks.