In the present study copper oxide nanoparticles (CuNPs) were synthesized via simple and eco-friendly green route using black tea extract . Characterization of synthesized nanoparticles (NPs) was undertaken. The characteristic absorption peak of CuNPs was in range (352-355) nm in UV–Vis spectrum. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies revealed the morphological and structural character of green NPs. The particle size was 25-50 nm. Energy dispersive spectroscopy (EDX) showed high intense metallic peak of copper (Cu), oxygen (O), carbon (C) and low intense peaks of phosphorus (P) , calcium (Ca) , sulfur (S), potassium (K) elements due to the capping action of biomolecules of plant extract in CuNPs formation. The X-ray diffraction (XRD) pattern showed distinctive peaks corresponding to (200), (220) and (311) planes revealing the high crystalline nature of synthesized CuNPs . The dyeing behavior of green CuNPs treated fabric with Acid Black 172 (AB 172) has been studied and the build up of dye, measured as exhaustion percentage (E%). Dye adsorption rate constants according to pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models were calculated. Moreover, the dye adsorption equilibrium data were fitted well to the Freundlich isotherm rather than Langmuir isotherm. The overall adsorption process follow pseudo-second order kinetics, Intraparticle diffusion and Elovich model. The CuNPs treatment produces a nylon fabric with advanced color fastness and antibacterial properties enabling them to improve human health care and reducing temperature, the environmental impacts, fabric damage, amount of dyestuff used and saving energy of conventional dyeing of nylon fabrics. This review focuses on green synthesis of CuNPs using environmentally benign reagents in minimal time paves the way for future studies on CuNPs toxicity without risking interference from potentially toxic reagents and capping agents. The use of this technique to treat nylon fabric may lead to new coloration technique and other functional improvement.