This nutritional study took place in the rural community centred on the village of Moshaneng in Southern District, Botswana. Arable and livestock agriculture are the traditional economic activities in this semi-arid environment in which highly seasonal and unreliable rainfall has a great impact upon settlement, economic activity and physical conditions. The primary objectives of fieldwork. were to assess nutritional status and to investigate the social, cultural, economic and physical environmental factors contributing to poor nutrition. As an ecological study, the main aim was to describe the multifactorial causes of malnutrition and the relationships between factors. Nutritional anthropometry was used to assess the nutritional status of children. Weight and height were the principal measurements. Subsequently, through three major questionnaire surveys, data were gathered on a) aspects of child care, maternal characteristics and perception, health status and dietary intake; b) household demographic structure, economic profile and economic status, food production, purchase and consumption, education and migration of household members; c) involvement in arable and livestock agriculture, constraints on food production, access to and quality of land, varieties of crops and production over.several seasons. Traditional beliefs and practices concerning diet, disease causation and treatment, and the social organisation of the community were also major areas of investigation. The majority of children were of poor nutritional status and mild to moderate protein-energy malnutrition (P.E.M.) affected approximately one third of the children assessed. At the individual level, poor weaning practices, inadequate supplementation of breast-fed children and inadequate qualitative and quantitative intake of food were identified as factors contributing to P.E.M.. Serious illness was widespread: respiratory infections, diarrhoea and skin infections were the major ailments. Illness and growth records show how recurrent and severe infections are interrelated with P.E.M. amongst children in this community. The vulnerability of children and their mothers is increased by high rates of illegitimacy and the lack of financial support from children's fathers. There were some misconceptions held about the appropriate foods for children but the main constraints to a better diet are economic and not educational. At the household and community levels several factors conspire to reinforce poverty, illhealth and an inadequate diet. Arable agricultural production is unable to meet the food needs of the local population who are forced to subsist on imported cereal staples of low quality: few households are self-sufficient in staple foods even in good years. Physical environmental factors, notably drought, poor soils and pests, reduce potential for arable agriculture but social and economic factors are the main constraints: inadequate and costly draught power and extensive, sub-optimal cropping systems. Highly maldistributed livestock ownership exacerbates the economic inequalities within the community and deprives many of access to milk, meat, draught power, and finance. Labour migration is a response to low returns from the traditional economiC sector but may increase the vulnerabilty of residual households.