The current research was conducted at the Ornamental Plants and Landscape Gardening Res. Dept. Nursery, Hort. Res. Inst., Agric. Res. Center, Giza, Egypt, over two consecutive seasons spanning from 2020 to 2022. The aim was to investigate the influence of NPK fertilization (0, 1.0, and 2.0 g/pot) and foliar spraying of an amino acids mixture (0, 1.0, and 3.0 ml/l), either applied individually or in combined treatments. This study focused on assessing their effects on vegetative growth, flower parameters, various chemical constituents, as well as the characteristics of bulbs and bulblets of Hippeastrum vittatum plants. The cultivation medium comprised a mixture of sand and clay (1:1 by volume), and the plants were grown in 20-cm pots. The results obtained indicated that various parameters were positively affected. This included an increase in height (cm), the number of leaves per plant along with their fresh and dry weights, the number of roots per plant along with their length (cm), the number of flowers per plant with their diameter (cm), and the length, as well as fresh and dry weights of flowering stalks (g). These improvements were observed when applying NPK fertilization at a rate of 2.0 g/pot, coupled with foliar spraying using an amino acids mixture at a rate of 3.0 ml/l. In this regard, the earlier treatment also led to an increase in bulb diameter (mm), along with its fresh and dry weights (g). Additionally, the characteristics of bulblets, including their number, diameter, and fresh and dry weights, showed positive effects. Moreover, the same treatment resulted in enhancements in various chemical constituents, such as chlorophylls, carotenoids in fresh leaves, total carbohydrates, and the percentages of N, P, and K in dry leaves and bulbs. Therefore, it is recommended to apply 2.0 g/pot of NPK fertilizer and foliar spray with a 3.0 ml/l amino acids mixture for the cultivation of H. vittatum plants in 20 cm-diameter plastic pots filled with sand + clay mixture (1:1 by volume).