A study was undertaken to understand the genetics of cotton fibre development at the University of AgriculturalSciences, Dharwad. The segregating F2 populations of the cross between fibred MCU-5 (WT) x fibreless mutant MCU-5(fl) and its reciprocal cross of upland cotton (Gossypium hirsutum L.) were evaluated to study the inheritance of the fibredevelopment. In both, straight and reciprocal crosses the segregation was in the ratio of 15 (fibred): 1(fibreless), indicatingduplicate dominant gene interaction signifying that the fibreless trait is controlled by double recessive genes. However,among the fibred plants presence of genetic variability for number of fibres per unit area was observed. It infers that, thepresence of individual cell level control over its elongation as a fibre. Scanning electron microscopy (SEM) was performedat fibre initiation stage, 2 DPA, to observe the development of fibre initials on epidermal layer of ovules. As compared toWT, SEM analysis revealed that the presence fibre cell initials in fl mutant was negligible.