Background: Intersectoral Action for Health (IAH) and its Health Impact Assessment (HIA) tool are built on collaboration between actors and sectors, requiring multidimensional and horizontal way of working. The study aims to analyse the enablers and barriers when such a new way of working and tool have been initiated to replace a traditional, vertical operation at the local level in Slovakia—a country in transition—in 2004. Methods: Up to date, there are few studies that have analysed intersectoral initiatives in relation to politics. In this study the conceptual framework of Kingdon has been used by which the actual problems, the governmental actions (or non-actions) (politics) and the understanding, implementation and evaluation of the initiative (policy) could be analysed. All actors involved, civil servants, politicians, representatives of the local public health institute and researchers, were interviewed and made to answer a questionnaire. Results: The results showed that there were a number of factors behind the initiation of HIA, which either delayed or accelerated the process. The problems identified were e.g. the prevailing traditional health care focus and the deteriorating health status of the population. There was a lack of multi-intersectoral knowledge, co-operation and function between sectors and actors. Enablers on the other hand were the membership of international organizations which called for new solutions, and the strong political commitment and belief that intersectorality would have a positive effect on health. Conclusion: The actors on the local level would have the capacity to work intersectorally to bring about policy change if HIA was to be more supported/institutionalized.