In this analysis of the global workforce, the Joint Learning Initiative-a consortium of more than 100 health leaders-proposes that mobilisation and strengthening of human resources for health, neglected yet critical, is central to combating health crises in some of the world's poorest countries and for building sustainable health systems in all countries. Nearly all countries are challenged by worker shortage, skill mix imbalance, maldistribution, negative work environment, and weak knowledge base. Especially in the poorest countries, the workforce is under assault by HIV/AIDS, out-migration, and inadequate investment. Effective country strategies should be backed by international reinforcement. Ultimately, the crisis in human resources is a shared problem requiring shared responsibility for cooperative action. Alliances for action are recommended to strengthen the performance of all existing actors while expanding space and energy for fresh actors.