Cotton fabrics were treated with air and argon atmospheric plasma for surface activation. Activated surfaces were grafted with two different amine compounds: ethylenediamine and triethylenetetramine. Pretreated cotton was dyed with acid dye and the effects of pretreatment on the colour strength, as well as the washing, rubbing and the light fastness of the dyeings, were investigated. Colour yield results showed that grafted ethylenediamine and triethylenetetramine enhance the dyeability of cotton fabric with acid dyes. Fourier transform infrared spectra confirmed the formed groups on the surface and scanning electron microscopy showed the etching effect of plasma.