Wastewater pollution has always been a major problem throughout the world. The lack of available water used for drinking, agriculture, farming, etc. has declined through the years. For the past several years, Turkey has been affected by the water pollution crisis. Particularly, together with the Metropolitan Municipality Law dated 07.10.2004 and numbered 5216, adjacent areas of metropolitan cities included new counties, towns, forest villages, and other villages, which in turn necessitated a revision of the current wastewater treatment alternativities. In this paper, domestic and industrial wastewater sources of Kayseri municipalities district were determined and information about the character and formation of the wastewater were provided. To our knowledge this is the first extensive study on wastewater characterization in this district. For this purpose, location of the declared facilities', their wastewater features, and discharging areas were investigated. Wastewater, existing throughout the city was divided into four parts and compared with the discharge standards which were determined by the national and local governments. Contamination levels differ with respect to sectors and the sector with the highest contamination level is found to be the textile industry. The fact that large textile industries became located within the city by expansion of adjacent areas has carried the problem to more serious dimensions. It is also observed that the food industry is important because of its water consumption and high load of organic contamination. Wastewaters of industries which are still discharging into the receiving water body should be connected to the sewerage system as soon as possible.