Pastoral adaptation is a unique technology of the traditional mode of food production, adjusted to fragile dryland environments for human sustenance, that exploits the patchy natural resource base of these ecosystems. Nevertheless, household food insecurity is a critical livelihood concern for pastoralist societies in Africa’s drylands. This chapter analyzes household food insecurity in the context of pastoralist societies, using a case study of Borana pastoralism. It begins with definitions and conceptualization, with a systematic focus on the evolution of food security ideas over the last six decades. It also touches on food security and culture, which are relevant to traditional pastoralist settings. It introduces current approaches to food security measurement and identifies their limitations, based on the globally adopted official definition of food security and cultural differences. The state of food security and hunger among Borana pastoralists is analyzed in detail using statistical evidence from our study area. This effort forms part of our broad approach in this book to systematically articulate the current state and welfare trends among these peripheral people inhabiting a fragile dryland habitat. The estimated results indicate that only 30% of the sample Borana households are considered food secure. The problem of food insecurity is more pronounced among the female-headed households. Moreover, even at normal times, approximately one-third of the respondent households may experience hunger.