Low research output among women researchers in health research has been linked to inadequate mentorship opportunities for early career women researchers and particularly in sexual and reproductive health and rights (SRHR) field. Mentorship has been recognized as a contributor to strengthening research capacity and as beneficial for both mentors and mentees. Women researchers oftentimes experience negative impacts of organizational and structural gender inequities related to formal and informal mentoring. In 2020, the UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction at WHO launched a mentorship programme for early career SRHR women researchers from low- and middle-income countries. The programme sought to provide professional skill-building, promote and share networking opportunities, and offer support in navigating personal and professional life. We conducted a convergent parallel mixed-methods evaluation of the 2020 pilot programme, which included 26 participants, through an online survey and semi-structured in-depth interviews (IDIs). Data collection occurred between March and May 2022. Nineteen responded to the online survey (12 mentees, 7 mentors) and 11 IDIs (7 mentees, 4 mentors) were completed. Based on a preliminary framework, we used deductive and inductive methods to identify six themes: views on mentorship; reasons for applying and expectations of participation in the programme; preferred aspects of programme implementation; challenges with the programme implementation; perceived lasting benefits of the programme; and recommendations for improvement. All participants found the initial training useful, most discussed work-life prioritization throughout the mentorship relationship, and most planned to continue with the relationship. There appear to be ample benefits to mentorship, especially when planned and implemented in a structured manner. These attributes can be particularly beneficial when they are conceived as a two-way relationship of mutual learning and support, and especially for women at the start of their research careers as they navigate structural gender inequities.