Background: Training and mentorship in research skills are essential to developing a critical mass of researchers in low-and middle-income countries (LMICs). However, reporting on the details of such training programs, especially regarding the cost of the training, is limited. Objectives: This paper describes a year-long operational research training and mentorship course in Rwanda, implemented between 2013 and 2017. Approach: We describe motivations for the design of the Intermediate Operational Research Training Course (IORT) across four iterations. We also report outputs, evaluate trainee experiences, and estimate training and mentorship costs. Findings: Of the 132 applicants to the course, 55 (41.7%) were selected, and 53 (96.4%) completed the training. The ratio of female-to-male trainees in the course increased from 1:8 in 2013 to 1:3 in 2017. Trainees developed and co-first-authored 28 research manuscripts, 96.4% (n = 27) of which are published in peer-reviewed journals. For the 15 trainees who completed the post-course evaluation, 93.3% and 86.7% reported improvement in their research and analytical skills, respectively. The median cost per trainee to complete the course was US$908