Utilization of grey water as an alternative source of water is a recent useful option to serve environmental sustainability, especially in water stressed and water scarce areas. Public acceptance is one of the key determinants of the success of grey water reuse. Surveys were conducted in the Turkish megacity Istanbul to investigate awareness and attitude of the public, and the impact of supplying information upon acceptance of grey water reuse. The major focus of the paper is placed on sources of grey water, possible final uses and economic considerations. The results revealed that the reuse of grey water as flush water was accepted the most with 79% which increased to 92%. The highest impact upon positive opinion was with acceptance on the reuse of grey water from washing machines with 93% change in approval after supplying information. The results reveal that informing public and awareness raising regarding grey water and its management are major factors for improving the level of acceptance.