In Zambia, under-?ve mortality declined from 1958 to 1975, rose from 1975 to 1992, before resuming its decline from 1992 to 2001. The study investigates the economic, political, and epidemiologic determinants of these changes. The rise in mortality could be explained by an economic downturn (declining income per capita, resulting from lower copper prices on international markets and decreasing production, and its numerous consequences), and to a lesser extent by emerging diseases (increasing mortality from HIV/AIDS and resistant malaria). However, mortality decline could resume as a result of building social and health capital, in particular health personnel, and favorable health policies