This thesis considers the nutritional, social and economic dimensions of seasona flood insecurity in Mali from the conceptual viewpoint of risk. It incorporates both longitudinal and crosssectional designs, and quantitative and qualitative methods to explore the strategies agriculturalists employ to minimize risk, and the characteristics of the vulnerable. Anthropometry, morbidity, adult energy expenditure, and household food consumption were monitored over a 14 month period in a village sample of 33 households to test the hypothesis that seasonal nutritional risk is experiencedd ifferentially by age and gender groups in the population. Significant seasonal changes were detected in all nutritional indicators, but few which exceeded threshold levels used to define risk. At the household level the thesis examines the hypothesis that exogenous factors and endogenous household characteristics combine to influence the range of strategies available to food insecure households, and therefore, the degree of risk they experience. Cross-sectional data on seven villages revealed striking interregional and interannual variations in the prevalence and severity of household food insecurity which are strongly related to rainfall. Household stratification according to the capacity to sustain a secure, adequate and viable diet revealed the food secure to be large and wealthy households with sufficient resources to diversify production, and to invest in agriculture and social networks of exchange. At the other extreme were food insecure households which tend to be poor, small and dependent on the proceeds of labour sales to breach the shortage period. Longitudinal study of food stock flows, labour exchange, monetary expenditure and other transfers, demonstrated the continuing vitality of social networks of exchange as means of spreading risk. Vulnerable households had less access to such networks.