Background: Hospitals generate relatively large quantities of WASTEWATER that may contain various potentially hazardous materials; therefore the proper management of hospital WASTEWATER is essential.Methods: In this cross-sectional study, the quality and quantity of WASTEWATER in the hospitals of Tehran University of Medical Sciences (TUMS), Tehran, Iran, were studied and the suitable method for WASTEWATER management in the hospitals was determined.Results: Monitoring of pH, TSS, BOD5, COD and total coliforms indicated that the quality of WASTEWATER in the hospitals was similar to domestic WASTEWATER. The WASTEWATER production in the hospitals was determined to be in the range of 398 to 1090 L/d/(occupied bed). The study on WASTEWATER treatment and disposal methods demonstrated that discharge to municipal WASTEWATER collection system is the best alternative for WASTEWATER management in the hospitals, but this approach is not applicable for all of the hospitals. Baharloo, Cancer Institute, Children, Farabi, Imam Khomeini, Razi, Roozbeh, Shariati and Valiasr hospitals can be connected to municipal WASTEWATER collection system at present.Conclusion: It is recommended that these hospitals’ WASTEWATER be discharged to municipal WASTEWATER collection system. Amir Alam, Bahrami, Mirza Koochak Khan and Sina hospitals will be able to discharge their WASTEWATER into sewerage network at second phase of Tehran sewerage project (in 2010) and Arash Hospital will be able to discharge its WASTEWATER into sewerage network at third phase of Tehran sewerage project (in 2015). These hospitals have to select onsite separate WASTEWATER treatment alternative.