The world's water resources are becoming scarce as a consequence of increased pressure by urban development, population increase, food production, and climate change. The result of this pressure is not only water scarcity on the quantitative site, but also quality deterioration. In this context, planned reuse of treated wastewater is gaining more and more attention and is a fast increasing practice worldwide because of being a sustainable use of water resources, and also an adaptive measure to the increasing water demand and climate change. However, wastewater reuse faces several challenges, with the most important one being health concern about the quality of the reused water. Reused water may contain hazards such as physical, chemical, radiological and microbial agents that can be a risk to human health. This is the reason for the development of guidelines and regulations for wastewater reuse in many countries. Additionally, international organizations have also developed guidelines for water reuse. Examples of major legislations and guidelines which are used as benchmark standards for other countries as well are those developed from the World Health Organization (WHO), The United States (US- EPA), California Title 22, Australia, The Food and Agriculture Organization (FAO), and The International Organization for Standardization (ISO). This thesis conducts a survey on a worldwide scale on the existing legislation on waterreuse and the quality standards applied by individual states and international and national organizations, the reuse schemes, and the water quality parameters applied in the main guidelines. It shows that the existing guidelines are very similar, and that a common and strong legislative base, instead of a convergence of water reuse regulations can help the further development of wastewater reuse worldwide and especially within the European Union, as a key component in urban water management, development, and trade in agricultural goods.