The aim of this study was to graft the amine functions on the surface of cellulose acetate (CA) fibers by two kind of plasma processing; namely, inductively coupled plasma (ICP) and radiofrequency plasma, using either NH3/He or mixture of N-2/H-2 gases. Optical emission spectroscopy was used to examine the various chemical species of the N-2/H-2 ICP system. Due to the entangled morphology of the CA fibers, only X-ray photoelectron spectroscopy (XPS) was used to characterize the surface. The effects of the different experimental conditions on the grafting efficiency have been studied. The results showed that in all cases NH2 groups were successfully grafted onto the surface of the CA fibers, and it seems that the ICP process is more effective for the amine grafting than low pressure radiofrequency plasma. Ageing tests carried out under laboratory conditions on the plasma-treated CA tow showed that the density of grafted amines was almost stable over a period of 60 days.