This paper describes the unfolding of two complementary efforts to build global capacity in health social science. The INCLEN model aims to infuse a genuine transdisciplinary perspective into international health through equipping social scientists to speak a common language with clinical epidemiologists and sensitising clinicians to the ways social sciences contribute to research and policy. Issues are raised pertinent to the model's viability, including recruitment of scholars for fellowships, curriculum substance, and mechanisms for integrating social science fellows when they return home. The future success of the INCLEN program, and comparable donor initiatives, depends upon a wider infrastructure of career supports played out at the international level in which donor and operating agencies nourish the emergence of an expanded body of health social scientists. The International Forum for Social Sciences in Health (IFSSH) has been formed to help build this infrastructure and provide impetus for a viable scientific community of health social scientists. The IFSSH 'global agenda' is portrayed and an illustration is given of how this agenda is being implemented in the Asia and Pacific region.