In order to ensure maximum consumer benefits (e.g. public health, livelihood), drinking water supply technologies in developing countries should be adopted taking into consideration locally available skills, resources as well as cultural and environmental settings. This paper presents case-studies from several developing countries in different geographical regions of water supply projects utilizing methods ranging from biological treatment offered slow sand filtration systems to chemically-assisted clarification. These examples reveal successes and lessons learnt in several research projects conducted under different settings (e.g. international development and humanitarian emergencies). In addition, the importance of capacity building for successful implementation of water treatment technologies is also illustrated.