This paper evaluates potential sources of effluent reuse and feasible reuse applications in Istanbul Metropolitan Area, within the framework of all technical issues that must be considered in the planning and implementation of water reuse systems. Some potential sources of effluent for reuse have been eliminated based on location, on treatment plant size, or both. An assessment made of future possible reuse applications in the vicinity of wastewater treatment plants now under construction or planned has identified the following possibilities: Tuzla; industrial, urban and groundwater recharge; Kucukcekmece; urban, industrial, recreational, augmentation; Buyukcekmece; urban, industrial, augmentation; Omerli - Elmaly; augmentation. The applications proposed for Istanbul have been based on technical, financial, economic, environmental and health considerations. The evaluation based on the current and anticipated programme of construction and commissioning of treatment facilities confirms that large scale reuse applications in Istanbul will not be a major consideration for the planning horizon. Copyright (C) 1996 IAWQ.