Mentoring is a unique educative workplace relationship which holds the potential to support the skill, knowledge, social and emotional needs of both new and experienced staff members. As promotion of mentoring in the nursing workplace can improve workforce retention and cohesion, understanding of nurse managers' perceptions of the barriers to the mentoring of early career researchers in hospitals can offer insights that enhance the efficacy of mentoring in these dynamic contexts. In-depth interviews with 20 nurse managers were conducted to identify these barriers, with interpersonal conflict, competing priorities for time and financial resources, and lack of training emerging as recurring themes raised by participants. We explore how these barriers can be mitigated to strengthen the contemporary mentoring quality and opportunity in acute care hospitals.