For many decades in Vietnam, rainwater harvesting has been widely used as a nature-based solution in rural areas, aiming at good-quality drinking water with low cost and little energy. Recently, rainwater for drinking has attracted much attention from the Vietnam government. Furthermore, despite its efforts, the outcomes are not as expected due to local barriers. This paper reviewed rainwater for drinking demonstration projects in some specific areas of Vietnam, with identification of the technical, economic, and social barriers, further suggesting possible overcome strategies. A lesson learnt from this study would be the principle of promoting rainwater for drinking in developing countries, looking forward to sustainability.