Greywater is an important water resource at the household level. The reuse of greywater is one of the most promising ways of conserving water because it has an important role in increasing plant productivity at the garden level. It is an important option to increase the efficiency of water use at the household level in rural Iraq. Through the implementation of a greywater treatment unit, this project sought to develop the treatment technology and encourage the local community in the target areas to reuse it. In this study, a greywater treatment unit that consists of a septic tank, up-flow anaerobic filter, and a storage tank is constructed on a specified area in the Khairi village in Al Diwaniyah province in Iraq. In order to ensure the quality of the treated greywater used in irrigation, an experimental verification and analysis of results were performed to demonstrate the improvement of physical, chemical and biological parameters. These parameters are COD, BOD, and TSS. According to the results of the study, the anaerobic filter (Subsurface Flow) was designed with one septic tank and three compartments. The total removal efficiency of COD, BOD, and TSS by greywater treatment unit was 92.27%, 96.9%, and 99.0%, respectively. The quality of the water produced by the greywater treatment unit was consistent with the FAO guidelines for reuse of treated water to irrigate domestic gardens.