Water scarcity and irregular geographical distribution is an increasingly pressing problem in arid and semi-arid regions. In lack of conventional water resources, especially for agricultural irrigation, water of marginal quality has to be considered. Strategies of mobilization and management of water resources worldwide are calling for reuse of treated effluents in agriculture to secure food production, especially in developing countries where climate change has become a challenge. Surface waters (lakes and rivers) and groundwater used for irrigation are also prone to point and non-point pollution through runoff and the discharge of insufficiently treated and untreated effluents from commercial facilities and treatment plants. Wastewater reuse is currently practiced worldwide, especially in developing countries following various patterns. In view of the large variety of pollutants entering the sewerage network and being transported to treatment plants, mineral and organic compounds end up in the receiving environment after or without transformation. Use of wastewater and discharge in the waterways are exposing the agricultural environment to substances of which many are still unknown with non-assessed impacts on the agro-ecological environment. Research on emerging pollutants, or as recently called contaminants of emerging concern, occurring in water and wastewater resources in developing countries have seen the light in recent years. Existing data on emerging pollutants are still scattered and only few classes of pollutants are identified and quantified in water resources so far. Studies on transformation products and antibiotic-resistances are still on the learning curve. Remediation of contaminated sites, through irrigation or spread of sewage sludge, including water bodies may call to advanced and innovative technologies taking into consideration local and regional circumstances. This Special Issue of the Journal CLEAN – Soil, Air, Water is grasping original research papers addressing emerging pollutants in terms of: (i) occurrence and distribution in natural environment, (ii) tools for monitoring and risk assessment in the environment, and (iii) removal for remediation of polluted sites. It contains selected papers that were presented at the International Symposium on Emerging Pollutants in Irrigation Waters: Origins, Fate, risks, and Mitigation held in Hammamet, Tunisia, 25-28 November 2013. The International Symposium was organized jointly by the Technical University of Braunschweig (TUBS), the National Research Institute for Rural Engineering, Water, and Forestry (INRGREF), Tunis, and the Higher Institute of Agronomy Chatt Meriem, Sousse, within the framework of the joint project EMPOWER Tunisia (EMerging POllutants in Water and wastewatER in Tunisia) funded by the German Academic Exchange Services (DAAD) through the German-Arab Transformation Partnership program. The symposium is deemed to be one of the first scientific events held on the topic of emerging pollutants in water resources in the Arab region. It has gathered 68 oral presentations and 24 posters from 13 countries. In order to allow papers of high-added value to be shared among the scientific communities, this Special Issue was open to other scientists, especially from developing countries, to share original papers addressing the emerging pollutants. A special acknowledgement is addressed to Prof. Dr. Müfit Bahadir, Director of the Institute for Environmental and Sustainable Chemistry, Technical University of Braunschweig (TUBS), Germany, Chairman of the project EMPOWER Tunisia, and former Editor in Chief of CLEAN Journal, for his kind invitation to be Guest Editor of this Special Issue. On his behalf, I address my sincere gratitude to Prof. Dr. Serge Chiron (France), Prof. Dr. Abdelmalek Dahchour (Morocco), Prof. Dr. Elke Fires (Germany), Prof. Dr. Christina Siebe (Mexico), and also to Assoc. Prof. Dr. Amitava Bandyopadhyay (India), Prof. Dr. Keith Cowan (South Africa), Prof. Dr. Gheorghe Duca (Moldovia), Prof. Dr. Blanca Jiménez-Cisneros (Mexico), Dr. Jarrod Miller (USA), Prof. Dr. Georgios Pilidis (Greece), Prof. Dr. Bülent Topkaya (Turkey), and Dr. Jeffrey Ullman (USA) for having dedicated time and efforts in managing the editorial and review processes. Sincerest thanks to all the reviewers for giving of their time and expertise for the evaluation of the manuscripts and for maintaining the high standard of the papers published by our journal. Guest Editor Dr. Olfa Mahjoub Co-chair of EMPOWER Tunisia INRGREF, Tunisia