There is increasing evidence suggesting that clinical mentorship (CM) involving on-the-job training is one of the critical resources-friendly entry points for strengthening the knowledge and skills of healthcare providers (HCPs), which in turn facilitate the delivery of effective reproductive, maternal, and newborn health (RMNH) care. The article explores the experiences of HCPs following participation in the CM program for RMNH in eight districts of Mwanza Region in Tanzania. A qualitative descriptive design employing data from midterm project review meetings and Key Informant Interviews (KIIs) with purposefully selected HCPs (mentors and mentees) and District Medical Officers (DMOs) during endline evaluation were employed. Interview data were managed using Nvivo Software and analyzed thematically. A total of 42 clinical mentors and master mentors responded to a questionnaire during the midterm review meeting. Then, a total of 17 KIIs were conducted with Mentees (8), Mentors (5), and DMOs (4) during endline evaluation. Five key themes emerged from participants' accounts: (i) the topics covered during CM visits; (ii) the benefits of CM; (iii) the challenges of CM; (iv) the drivers of CM sustainability; and (iv) suggestions for CM improvement. The topics of CM covered during visits included antenatal care, neonatal resuscitation, pregnancy monitoring, management of delivery complications, and infection control and prevention. The benefits of CM included increased knowledge, skills, confidence, and change in HCP's attitude and increased client service uptake, quality, and efficiency. The challenges of CM included inadequate equipment for learning and practice, the limited financial incentive to mentees, shortage of staff and time constraints, and weaker support from management. The drivers of CM sustainability included the willingness of mentees to continue with clinical practice, ongoing peer-to-peer mentorship, and integration of the mentorship program into district health plans. Finally, the suggestions for CM improvement included refresher training for mentors, engagement of more senior mentors, and extending mentorship beyond IMPACT catchment facilities. CM program appears to be a promising entry point to improving competence among HCPs and the quality and efficiency of RMNH services potentially contributing to the reduction of maternal and neonatal deaths. Addressing the challenges cited by participants, particularly the equipment for peer learning and practice, may increase the success of the CM program.