The crippling famines of the 1970s and 1980s in sub-Saharan Africa (SSA) prompted the development of national and regional early warning systems (EWS) across the continent. Generally, these systems have been effective in alerting countries and donors to impending food crises largely in the context of seasonal droughts, helping to mitigate adverse impacts. There are, however, important exceptions that suggest that inadequate early warning analysis, together with poor communication and ineffective coordination and response mechanisms, have often contributed to acute food security emergencies that might have been prevented. In addition, several key emerging issues pose increasing challenges to EWS in SSA, including the continued susceptibility of African agriculture to climatic variability and other hazards, the vulnerability of millions of chronically impoverished and malnourished households to a variety of threats, and the impacts of economic liberalization and globalization on African households.