[en] Full text: Quaternary ammonium groups, well known antibacterial agents, have been incorporated covalently onto cotton fabric via radiation induced grafting of (2-(Acryloyloxy)ethyl)trimethylammonium chloride (AETC) on to cotton fabric by mutual irradiation grafting technique using ⁶⁰Co-gamma radiation source in presence of 2- Hydroxyethylmethacrylate (HEMA). Various experimental parameters have been optimized for development of antibacterial grafted cotton fabric. Grafting extent increased with dose but was an inverse function of dose rate. Grafting yield increased linearly with HEMA concentration but was not affected by AETC concentration in feed. N₂ ambient was most effective during grafting. The grafted sample show significantly higher water uptake and water retention properties. Antibacterial activity of polymer, co-polymer and grafted samples were tested against four bacteria S. aureus, E.coli, B.cereus and P.fluorescens. The minimum bactericidal concentration (MBC) of poly(AETC) was in range 0.0025-0.2% depending on the bacteria. MBC followed the order S.aureus ∼ B.cereus< E.coli< P.fluorescens. The co-polymer of AETC and HEMA was found to be effective against S.aureus and B.cereus only. Antibacterial assay showed variations in activity between pure polymer and grafted cotton. The activity of grafted samples was less in comparison pure polymer, which may be due to its bound state on cotton