The current investigation was conducted during 2022 and 2023 at the experimental research farm of Ali Mubarak EL-Bostan area to quantify the effect of different water stress levels before harvest (during flowering stage) of geranium plant grown in sandy soil on geranium plant growth, its essential oil content and composition when the plant was exposed to six different levels of water stress (100, 70, 60, 50, 40 and 30% of ETo) for four weeks before harvesting between bud initiation and flowering stage. Water stress levels had insignificant alteration on growth characteristics during the last four weeks before harvesting. It could be observed from the obtained results that when geranium plants were subjected to water stress level (50% of ETo) the essential oil content trended to maximize (0.26-0.30%). Also, water stress altered essential oil composition. Water stress level (50% of ETo) increased geraniol and lowered citronellol since increasing water stress accelerated the transformation of hydrocarbons (α-pinene, β-Pinene, Ocimene, limonene and β-Caryophyllene) to their oxygenated constituents, water stress level (50% of ETo) maximized antioxidants content. It could be concluded that water stress at (50% of ETo) for four weeks before harvesting geranium when correctly timed and appropriate level could increase essential oil content and improve its quality.