This study aims to determine by means of a randomized trial the impact of reducing such barriers on morbidity due to severe malaria among children 6 months to five years and on outpatient utilization. An existing pre-payment scheme in the study area will be utilized to improve financial access for half of 2500 households who have not registered for either year I or II. The impact on severe anaemia, mean haemoglobin and anthropometric measurements will be assessed. Health service utilisation rates will be measured in both groups by active and passive surveillance. Patient perceptions and health-seeking behaviour will be compared. The study will contribute to the current debate on the relative importance of cost of care as a barrier to health care and the potential for the removal of this barrier as a strategy for malaria control, and on methods to optimise this.