Formulation and implementation of local health policies is frequently influenced by cooperation programmes established between countries or between private entities having specific interests for the offering country as well as for the receiving country. The purpose of this paper is to analyse the objectives and characteristics of US cooperation in public health with Colombia, between 1939 and 1945.The significance placed by the US (as well as by the Colombian government) on inter-americanism is examined, this being the foundation of many health cooperation programmes. From this standpoint an attempt is made to clarify why health cooperation became part of the agenda in discussions concerning hemispherical security and the impact of such programmes on local health policy development in Colombia. The means of negotiation between economic and political interests and their effect on the development of public health policies in Colombia is also analysed.