The DASH study, or in full the Disease, Activity and Schoolchildren’s Health in Port Elizabeth, South Africa, is a joint research project between the University of Basel, Switzerland, the Swiss Tropical and Public Health Institute in Basel, Switzerland, and the Nelson Mandela University in Port Elizabeth, South Africa. The aim of the project is to assess the burden and distribution of communicable diseases and non-communicable chronic conditions among approximately 1,000 primary school-aged children in selected underprivileged schools near Port Elizabeth, South Africa, and to assess their effect on children’s physical fitness, cognitive performance and psychosocial health. Furthermore, the impact of key interventions, e.g. (1) physical education programme, (2) health and hygiene and education and (3) nutritional intervention, on overall child health will be estimated.