Water stress in semiarid areas limits eggplant productivity for which the application of amino decanate® has shown significant improvement in yield but, the concentration and intensity is not yet standardized. A field trial was conducted during 2018 in greenhouse condition located at Fallujah city, Iraq to study the effects of water stress (50, 75, 100% based on field capacity) and rate of foliar application of amino decanate® (0, 100 and 200 mg/L) on vegetative growth and production of eggplant. The results revealed that 100% irrigation level recorded higher plant height (65.70 cm), stem diameter (8.05 mm), chlorophyll content (73.48 SPAD) with increased yield (5.78 t/ha) and water use efficiency (WUE) (5.99 kg/m3). The foliar application of 200 mg/L amino decanate® rate increased plant height (73.49 cm), stem diameter (7.84 mm), chlorophyll content (62.99 SPAD) and yield (5.44 t/ha). Interaction effect of 100% irrigation level and foliar application of 200 mg/L amino decanate® treatments produced higher plant height (83.99 cm), stem diameter (9.92 mm), chlorophyll content (85.11 SPAD) and yield (7.12 t/ha). The maximum WUE (7.67 kg/m3) was produced at 100% irrigation level with foliar application of 100 mg/L amino decanate® concentration. The vegetative growth, yield and WUE of eggplant under water stress conditions increased with increasing concentrations of amino decanate®.