This paper studies variation in risk assessment by pastoralists in the arid and semi arid lands of southern Ethiopia and northern Kenya. Despite superficial homogeneity among east African pastoralists, we show that there exists considerable within-group heterogeneity in their assessment of various risks. We conceptualise risk as comprising of four distinct components: objective exposure, subjective perception, ex ante mitigation capacity, and ex post coping capacity. This conceptualisation provides an effective framework for understanding the observed heterogeneity as the natural consequence of (sometimes modest) structural differences in economic activity patterns, agroclimatic conditions, proximity to towns, wealth, and gender roles. It therefore provides a useful tool for drawing out the policy implications of subjects' expressed concerns about prospective livelihood hazards.