It is vital to limit the loss of mineral NPK fertilizers during crops fertilization, especially in adverse soil conditions that reduce its availability to plants uptake and increase environmental pollution impact. This study aimed to reduce the soil application of the traditional NPK (TNPK) fertilizers through partially adding foliar nano chitosan-NPK (NCS-NPK) with plant growth promoting rhizobacteria (PGPR) to boost cotton (Gossypium Barbadense L.) productivity and fiber quality. During the growing seasons of 2021 and 2022, field experiments were performed at the Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt. A split-plot with four replicates based on a Randomized Complete Block design was used. Egyptian cotton cultivars Giza 97, 96 and promising hybrid G93xG71 were assigned to main plots, and seven foliar NCS-NPK and PGPR treatments were distributed in subplots. Results showed superiority of Giza 97 cultivar in boll weight (3.38 g), seed cotton yield fed-1 (11.13 ken), maturity ratio (0.94) and fiber elongation (7.85%), while Giza 96 cultivar in uniformity index (86.62%) and fiber strength (46.57g/tex) and promising hybrid G93xG71 in plant height (146.7cm), sympodial branches plant-1 (15.26), seed index(10.84 g), lint% (36.08%), upper half mean (UHM) (35.48 mm), fiber fineness (3.17), and fiber brightness (reflectance degree Rd %, (76.40%). Foliar combined NCS-NPK with PGPR under 50% T-NPK gave the highest values of the most studied treats. There is evidence that the combined application of NCS-NPK with PGPR can reduce the application of T-NPK fertilizers, which sequentially reduce environmental pollution and enhance cotton production and fiber quality. [ABSTRACT FROM AUTHOR]