The Water Supply and Sanitation Project being implemented by the Christian Community Services (CCS) tested and introduced SODIS to rural communities in the North Rift Area of Kenya from 2001 to 2004. When introducing SODIS to the women groups, their first question was "Does it work?" Bacteriological tests were undertaken on the raw water from rain water tanks, natural springs and shallow wells and compared to the same water treated by SODIS; SODIS was effective in killing diarrhoea causing pathogens. People using SODIS to treat their drinking water signifi cantly could improve their health. Their incidence of diarrhoea was reduced by more than 60%. From the perspective of rural women comparing different techniques of water disinfection, SODIS was found to be to most useful and efficient. It has proved to be a simple, cheap, renewable and environmentally friendly technique to reduce the risk of waterborne diseases.