GROWTH promoters or biostimulants have been called for the supplements that contain nutrients, amino acids and plant extracts. One of them would be taken into consideration to increase the production of plants is the growth promoter VIUSID agro. To study the effect of VIUSID agro on the maize grain yield (ton ha-1) as well as grain quality, two field experiments were carried out in the experimental field of Agric. Res. Stat., Fac. Agric., Cairo Univ., Giza, Egypt in 2015 and 2016 seasons.With this aim, five maize cultivars (Namely, the single cross hybrids SC-30k9, SC-110, SC-30k8, the three way cross hybrid TWC-310 and the open-pollinated composite Cairo-1) were evaluated under four dosages, i.e., 0.0, 0.96, 1.44 and 2.0L ha-1 of foliar spraying of theVIUSID agro. Means under the dosage of 0.96L ha-1 of theVIUSID agro significantly exceeded the control by 26.19% for grain yield ha-1 (GYH), 8.89% for grain protein percentage (GP%), 45.39% for protein yield/ha, 3.14% for grain oil percentage (GO%), 40.44% for oil yield ha-1 (OYH) and 33.29% for carbohydrate yield/ha. It was concluded that increasing maize yield ha-1and grain quality in the present investigation could be achieved by applying the low dosage (0.96L ha-1) of VIUSID agro.