The paper uses a case study of the development of syndromic management for treating sexually transmitted infections (STIs) and subsequent policies recommending worldwide use of syndromic management guidelines. These treatment policies emerged in the late 1970s from researchers and public health physicians working in sub-Saharan Africa where they had to treat large numbers of STIs in difficult circumstances. Syndromic management was initially developed in specific local epidemiological and resource situations. By the late 1980s, the World Health Organization had adopted syndromic management as policy, and began to promote it globally in the form of algorithms and training guidelines. Dissemination was assisted by the context of the rapid spread of HIV/AIDS and the apparent effectiveness of syndromic management for treating STIs and slowing the transmission of HIV/AIDS. In the mid 1990s, international donors interested in HIV control and women's reproductive health took it up, and encouraged national programmes to adopt the new guidelines. Implementation, however, was a great deal more complex than anticipated, and was exacerbated by differences between three rather separate policy networks involved in the dissemination and execution of the global guidelines. The analysis focuses on two parts of the process of policy transfer: the organic development of scientific and medical consensus around a new policy for the treatment of STIs; and the formulation and subsequent dissemination of international policy guidelines. Using a political science approach, we analyze the transition from clinical tools to global guidelines, and the associated debates that accompanied their use. Finally, we comment on the way current global guidelines need to be adapted, given the growth in knowledge.