The hybrids of medium-fiber cotton were assessed in terms of fiber quality in the Tashkent, Fergana and Kashkadarya regions of the Republic of Uzbekistan. 4 hybrid combinations of different genetic origin were tested. The analysis of the influence of the genotype and the environment on the manifestation of the qualitative parameters of the fiber (length, specific breaking load, micronaire) was carried out. High values were found in hybrids involving the wild species G. trilobum Skovsted and the ruderal form G. Harknessii Brand. as well as varieties Bukhara-6. As a result of three years of experiments, it was found that the genotype and unaccounted factors influence the variability of the fiber length to a greater extent. The genotype rather than the environment significantly affects the specific breaking load of the fiber. The variability of the micronaire fiber is more dependent on environmental conditions.