Human resources for health are necessary to the delivery of health services; only by securing a sufficient, equitably distributed, adequately supported and well-performing health workforce can any health goals and targets set by national governments or the international community be met [1]. In spite of the recognition of this central role in attaining health outcomes, investments in human resources for health have been and still are constrained by the perception that the health economy (and the health workers within it) is a consumptive sector, whose costs governments should strive to contain, rather than a contributor to socio-economic development in its own right. This thematic series sought to examine and broaden the evidence on the contribution of investment in human resources for health to broader development outcomes in other sectors, including synergies with education, finance, employment, gender empowerment and peace building.