Public contribution in research can lead to the design and conduct of more feasible and relevant research. However, our understanding of the acceptability and feasibility of public contribution and the evidence base regarding its impact in low- and middle-income countries (LMICs) is limited. In this study protocol, we describe a mixed-method examination of public contribution activities in the GuardiansCan project. The GuardiansCan project aims to respond to Tanzanian guardians' poor adherence to children's follow-up care after treatment for acute lymphoblastic leukemia (ALL) with the help of Mobile Health technology. We aim to: (1) involve guardians of children treated for ALL as Guardians Advisory Board (GAB) members in the managing and undertaking, analysis and interpretation, and dissemination phases of the GuardiansCan project; and (2) examine the acceptability, feasibility, and perceived impact of GAB members' contribution to the GuardiansCan project from the perspective of the GAB members and public contribution coordinators. We will recruit six to eight guardians of children treated for ALL to the GAB. We will hold workshops where GAB members contribute to all project phases. Using impact logs, we will record GAB workshop activities and the perceived impact of these activities. We will interview GAB members and public contribution coordinators 6 months after establishing the GAB, and at the end of each study within the project, to examine the acceptability, feasibility, and perceived impact of public contribution activities. We expect GAB contribution to increase project quality and relevance, and inform how to best embed public contribution in research in LMICs.