Impact evaluation is increasingly requested from research for both donor and social accountability (Faure et al., Agric Syst 165, 128-136; 2018). Conducting it properly is difficult, especially in the context of a developing country. Quantitative studies are often biased toward expected and tangible impacts. Complementary and more qualitative approaches are focused on understanding causality and are more in line with actors' participation in impact evaluation. CIRAD has developed a method (ImpresS) and applied it to assessing 13 case studies, each of them including a cluster of projects involving research and conducted in widely different environments (Faure et al., Agric Syst 165, 128-136; 2018). One of the case studies looked at the impacts of the use of innovative evaluation approaches to strengthening animal health surveillance. This research was implemented by Cirad and its partners between 2009 and 2016 in order to develop innovative evaluation approaches to evaluate animal health surveillance systems in South East Asia (REVASIA: ). In this chapter, we present how the impact evaluation approach based on the theory of change can help in framing surveillance programs and also how this approach can be used to assess the impact of the evaluation itself.