Thermal analysis, mechanical behavior, and dyeing performance of nylon–graft-polyacrylonitrile (nylon–g-PAN) copolymers having different graft yields have been studied. The results of the thermogravimetric analysis (TGA) revealed that the weight loss decreased from 88.11% for ungrafted sample to 69.26 and 58.93% for nylon–g-PAN samples having 31.6 and 58.4% graft yields, respectively. Differential scanning calorimetry (DSC) of all grafted samples shows exothermic peak at 270°C. This peak is absolutely absent for the ungrafted sample. The air permeability values were decreased via grafting. The water permeability and bursting strength values decreased from 12.7 (mbar) and 1331 kiloPascal for ungrafted fabric to 9.75 (mbar) and 921 kiloPascal, respectively, for nylon having 8.4% graft yield. By increasing the graft yield, the water permeability and bursting strength values were gradually increased up to 11.3 (mBar) and 1168 kiloPascal for nylon having 20% graft yield. The dyeing performance of the disperse dye was evaluated.