This paper reviews vulnerability concepts and relates these to proximate as well as long run factors implicated in the food security crisis in southern Africa. Vulnerability is not the same as poverty or food insecurity that describe livelihood states at a particular point in time. Vulnerability is a ‘forward looking’ concept that seeks to describe how prone individuals and families are to being unable to cope with uncertain adverse events that may happen to them, like prolonged lack of rainfall, or infection by the AIDS virus. The paper adopts the Devereux (2002) definition of vulnerability as “the exposure and sensitivity to livelihood shocks”. In this, the sensitivity component is critical, since it denotes that a small adverse shock will have a large adverse effect on the survival capabilities of the people that it strikes.