Every year, about a million children under 15 years are diagnosed with Tuberculosis (TB) worldwide, and about a quarter die. However, over 60% of children with TB remain undiagnosed, particularly in sub-Saharan Africa, which accounts for about 20% of the global burden of paediatric TB cases. In 2022, WHO issued an interim general recommendation to use integrated Treatment-Decision Algorithms (TDAs) to diagnose TB in children under 10 years. However, this recommendation was based on very low certainty of evidence. Therefore, we are seeking funding to address four objectives: 1) To compare the effectiveness of TDAs and the Standard of Care in routine clinical settings 2) To identify processes and contextual factors that influence the effectiveness and fidelity in the implementation of TDAs 3) To compare the costs, cost-effectiveness, and the population level impact of the TDA strategies on the burden of TB and 4) To validate the diagnostic performance (sensitivity, specificity, negative and positive predictive values) of the TDAs in various health system settings and clinical context. A four-year pragmatic open-label cluster randomized controlled trial will be conducted in 120 primary health facilities in Tanzania, Uganda, and DR Congo. The primary outcome is the proportion of children detected and initiated on TB treatment. About 60,000 children with presumptive TB will be screened. We anticipate that this project will yield results that address the issue of low detection rates of paediatric TB in sub-Saharan Africa and beyond, build research capacity in conducting implementation research in low-income countries, and foster networking and collaboration between the partner institutions.