Diarrhoeal diseases are a global public health burden, killing 1.8 million people annually. Diarrhoea disproportionately affects children and those in poverty. Most diarrhoeal cases can be prevented through safe drinking water and basic hygiene and sanitation measures, with drinking water interventions having the most impact on reducing diarrhoeal disease. A metaevaluation of studies assessing a specific household water treatment method, the biosand water filter, was completed. Results from the meta-evaluation illustrated that biosand water filters improve drinking water quality and reduce diarrhoeal disease. However, short follow-up times and inconsistent measures are a concern. Furthermore, there is no generally accepted field method for determining biosand water filter effectiveness that is useable in low-resource communities. This study adds to understanding of biosand water filters.