Background: This presentation examines the policy dynamics of suicide prevention within the context of the regulation of pesticides in Sri Lanka.Suicide in Sri Lanka is a major public health problem and in 1995 the country had one of the highest rates of suicide worldwide.Recent reductions in overall suicide rates have been attributed to the regulations of pesticides.The evolution, structure and implementation of the policy decisions that supported this successful action are explored in an attempt to provide a conceptual framework for successful policy action.Methods and Results: An explanatory case study methodology was used with in-depth interviews and document reviews.A semi-structured interview framework was developed based on the Overseas Development Institutes context, evidence and links model.14 key informants were interviewed.Four distinct periods of policymaking on this issue were identified; a muddling through phase, a capacity building phase, an agenda-setting phase and an evidence informed policy-making phase.Conclusion: The policy response to extremely high rates of suicide from intentional poisoning with pesticides in Sri Lanka highlights successful policy action.It shows a unique and successful example of evidence-informed policymaking, under the radar, that is characterised by several building blocks -structures, capacity, key participants and an epistemic community.These building blocks enabled evidence informed policymaking to thrive and suggest that a longer timeframe and an appreciation of socio-cultural factors are required to embed evidence informed approaches.