Although the Millennium Development Goal (MDG) target for drinking water was met, in many developing countries water supplies are unreliable. This paper reviews how households in developing countries cope with unreliable water supplies, including coping costs, the distribution of coping costs across socio-economic groups, and effectiveness of coping strategies in meeting household water needs. Structured searches were conducted in peer-reviewed and grey literature in electronic databases and search engines, and 28 studies were selected for review, out of 1643 potentially relevant references. Studies were included if they reported on strategies to cope with unreliable household water supplies and were based on empirical research in developing countries. Common coping strategies include drilling wells, storing water, and collecting water from alternative sources. The choice of coping strategies is influenced by income, level of education, land tenure and extent of unreliability. The findings of this review highlight that low-income households bear a disproportionate coping burden, as they often engage in coping strategies such as collecting water from alternative sources, which is labour and time-intensive, and yields smaller quantities of water. Such alternative sources may be of lower water quality, and pose health risks. In the absence of dramatic improvements in the reliability of water supplies, a point of critical avenue of enquiry should be what coping strategies are effective and can be readily adopted by low income households.