This work evaluates the potential for rainwater harvesting at the household level in the dry climate of Saudi Arabia. The amounts of rainwater that can be harvested in several cities in Saudi Arabia were estimated and it was found that a significant volume, exceeding 7.5 m(3)/100 m(2) per year, can be harvested. The per cubic meter cost of harvesting rainwater was compared to that of producing desalinated water. It was found that harvested rainwater is cheaper to capture than desalinated water produced from renewable energy-driven desalination plants, but that is not the case for fossil fuel-powered desalination. The study also considered the effects of rainwater harvesting on mitigating floods and reducing greenhouse gas emissions. A cost-benefit analysis of installing rooftop rainwater harvesting systems in Saudi Arabia was performed. It revealed that it is economically feasible to harvest rain in cities including Hail, Jeddah, Taif, and Riyadh, while it is not recommended in the holy cities of Makkah, Medina, and Buraidah.