This paper aims to evaluate the water quality of domestic RO units used in Jordan along with bottled and tap water. Analyses of the quality of water sources (RO, bottled and tap) and water cost are carried out. The methodology of this research is based on both lab experimental analysis and field survey of several RO units. It was concluded that all samples from the three sources are in compliance with Jordanian Standards. However, one type of bottled water and RO produced water are below the allowable limits with regard to all chemical properties. Tap water exceeds the allowable limit with regards to both total hardness and TDS, but is still below the allowable limits in case no better resource is available. However, with regard to pH and chloride concentrations, tap water is below the allowable limits. Based on quality and cost, it was found that RO produced water provides water within the allowable limits with a relatively reasonable price.