In the context of climate variability and change, application of treated wastewater for irrigation is an appropriate approach to cope with the water scarcity in arid and semi-arid regions. Farmers will adopt treated wastewater if they perceive it as an economically beneficial, socially acceptable, environmentally sound, and have little or no health risks. However, few studies have investigated the sustainability of wastewater irrigated farms. Also, almost all the studies have focused only on the farmers’ attitude or field observation data, which can underestimate the wastewater impacts on the agricultural sustainability. Therefore, the aim of this study was to investigate farmers’ attitude towards economic, social, environmental and health sustainability of wastewater irrigated farms. To prevent misleading, the economic and environmental impacts of wastewater were validated with real field observations. A survey of 197 wastewater and freshwater users of Marvdasht County, Iran, selected through a systematic random sampling method indicated that wastewater users had more positive attitude towards the economic, social and environmental sustainability of wastewater irrigated agriculture. However, field data analysis did not support the farmer’s optimistic views and revealed that long-term application of wastewater could intensify the concentration of heavy metals in the soil and water, reduce the quality of soil, plant and water and also threat the farmers and consumer’s health. This implies that sustainable implementation of wastewater use projects depends on the psychological support of the farmers and consideration of real impacts of the wastewater resources on the human and environment. Some recommendations are offered to improve sustainable wastewater management.