Public health surveillance systems are essential for monitoring diseases and outbreaks in Tanzania, where resources are often limited. However, their adoption varies among different regions and institutions. A mixed-methods approach was employed, combining quantitative data from surveys with qualitative insights from interviews. Data were collected from healthcare facilities across three regions in Tanzania, representing diverse health systems. The findings indicate that adoption rates varied significantly by region (30% in rural areas vs. 50% in urban areas), primarily influenced by local governance structures and resource availability. Interviews revealed challenges related to training and support for staff. This study provides a comprehensive methodological framework for evaluating public health surveillance systems, highlighting the importance of tailored interventions based on regional context. Health authorities should prioritise targeted training programmes and logistical support in underserved regions to improve system adoption and effectiveness. public health surveillance, Tanzanian settings, quasi-experimental design, adoption rates, healthcare facilities Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.