Antibacterial textiles are gaining increasing importance due to consumer awareness of health and hygiene. Cellulose-containing polymers, like bamboo rayon, are prone to microbial attack which restricts their application in medical textiles. Metal nanoparticles are widely used for antibacterial modification of textile polymers; however, less durability to washing is considered to be a severe limitation. In the current study, bamboo rayon fabric grafted with acrylic acid was utilized as a backbone to immobilize copper nanoparticles. The modified product was characterized using Fourier transform infrared, thermo gravimetric analysis and scanning electron microscopy analysis. The change in appearance of the fabric was measured using a spectrophotometer. The grafted bamboo rayon-Cu nanoparticles composite fabric was then evaluated for antibacterial activity against both Gram positive and Gram negative bacteria and the durability of their antibacterial activity to washing. The product showed antibacterial activity against both types of bacteria which was found to be durable till 50 washings. The release study showed lower release of nanoparticles in aqueous media indicating better immobilization of nanoparticles on grafted bamboo rayon. The material can be claimed as suitable candidate for medical textile applications to prevent cross infections.