The crippling famines of the 1970s and 1980s in sub-Saharan Africa (SSA), which claimed the lives of millions of people and forced millions more into destitution, prompted the development of early warning systems (EWS) across the continent. Governments, regional institutions and development partners have invested extensively in establishing EWS as a critical element of the emergency response system over the past three decades. Today, there is a wide presence of EWS across SSA and evidence suggests, albeit with well- acknowledged exceptions, that these systems have been largely effective in alerting countries and donors to impending food crises (largely in the context of seasonal droughts), helping to mitigate adverse impacts. Notably, the recurrence of large-scale famines has been prevented, in part due to the functioning of these EWS systems. 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. The well-documented examples include Ethiopia in 1999/2000, Malawi in 2001/2002 and Niger in 2005 . Learning from the breakdowns in early warning and response systems can lead to improvements in their future operation and performance. In addition, EWS are increasingly challenged by several emerging issues, such as the continued susceptibility of African agriculture to climatic variability and other hazards and the vulnerability of millions of chronically impoverished and malnourished households to a diversity of threats, from HIV/AIDS to prolonged violent conflict.