Adopting a high-density planting system in cotton cultivation has resulted in increased yields compared to traditional methods. Despite the clear benefits, farmers face various challenges throughout the cultivation process, from sowing to harvesting. However, selecting appropriate plant spacings, fertilizer levels and implementing tailored cultivation techniques can significantly enhance productivity. A field experiment was conducted at Siddapur research farm, Regional Agricultural Research Station, Warangal, Telangana, India during kharif 2023 to investigate the “Impact of different plant densities and fertilizer levels on yield attributes, yield and fibre quality characters of cotton in high density planting system (HDPS)”. The experiment was laid out in randomized block design (factorial) and replicated thrice, consisting of 12 treatment combinations comprising of three plant spacings S1: 80 x 20 cm (62,500 plants ha-1), S2: 90 x 15 cm (74,074 plants ha-1), S3: 90 x 60 cm in factor I and four fertilizer levels (F1: 100%RDF, F2: 125%RDF, F3: 100%RDF + Microbial consortia, F4: Control) in factor II. Both the factors significantly influenced the number of bolls per plant, number of bolls m-2 and seed cotton yield per hectare. The results revealed that higher no. of bolls plant-1 were recorded in 90 x 60 cm (18,518 plants ha-1) however, higher no. of bolls m-2, seed cotton yield (2233 kgha-1) obtained from higher plant density (74,074 plants ha-1) with the spacing 90 x 15 cm. Boll weight was not significantly influenced by varied plant spacings and fertilizer levels. Among the different levels of fertilizer, 125%RDF recorded highest no. of bolls per plant, no. of bolls m-2 and seed cotton yield (2362 kgha-1). Fibre quality characters viz., Upper half mean length(mm), micronaire(µginch-1), tenacity(gtex-1) and uniformity index (%) were not significantly influenced by both plant spacings and fertilizer levels as they are primarily governed by genetic makeup of cotton genotypes. For optimum seed cotton yield, cotton should be sown at closer spacing 90 x 15 cm and the application of 125%RDF was economically feasible in high density planting system.