Background: In high-income countries (HICs), increased rates of survival among pediatric cancer patients are achieved through the use of protocol-driven treatment. Compared to HICs, differences in infrastructure, supportive care, and human resources, make compliance with protocol-driven treatment challenging in low-and middleincome countries (LMICs). For successful implementation of protocol-driven treatment, treatment protocols must be resource-adapted for the LMIC context, and additional supportive tools must be developed to promote protocol compliance. In Tanzania, an LMIC where resource-adapted treatment protocols are available, digital health applications could promote protocol compliance through incorporation of systematic decision support algorithms, reminders and alerts related to patient visits, and up-to-date data for care coordination. However, evidence on the use of digital health applications in improving compliance with protocol-driven treatment for pediatric cancer is limited. This study protocol describes the development and evaluation of a digital health application, called mNavigator, to facilitate compliance with protocol-driven treatment for pediatric cancer in Tanzania. Methods: mNavigator is a digital case management system that incorporates nationally-approved and resourceadapted treatment protocols for two pediatric cancers in Tanzania, Burkitt lymphoma and retinoblastoma. mNavigator is developed from an open-source digital health platform, called CommCare, and guided by the Consolidated Framework for Implementation Research. From July 2019-July 2020 at Bugando Medical Centre in Mwanza, Tanzania, all new pediatric cancer patients will be registered and managed using mNavigator as the new standard of care for patient intake and outcome assessment. Pediatric cancer patients with a clinical diagnosis of Burkitt lymphoma or retinoblastoma will be approached for participation in the study evaluating mNavigator. mNavigator users will document pre-treatment and treatment details for study participants using digital forms and checklists that facilitate compliance with protocol-driven treatment. Compliance with treatment protocols using mNavigator will be compared to historical compliance rates as the primary outcome. Throughout the implementation period, we will document factors that facilitate or inhibit mNavigator implementation.