Abstract In this paper the hydrophilic improvement of the grey cotton fabric by low pressure dc glow discharge air plasma is investigated. The fabrics were treated for different exposure times, discharge potentials and pressure levels. Effect of plasma treatment on the wettability of the fabric was studied by measuring contact angle and dynamic wicking rate. The surface energy values have been estimated using contact angle measurements and effective mean pore radius of the plasma-treated fabrics were estimated by modified Washburn equation via dynamic wicking technique. Degradation and dyeability of the fabrics were determined by weight loss percentage and computer colour matching procedure. Characterization of the functional changes due to the plasma treatment has been carried out by means of Fourier transform infrared spectroscopy (FTIR–ATR). The surface morphology of the untreated and plasma-treated fabrics were analyzed by scanning electron microscopy (SEM).