This article deals with plasma treatment of polypropylene fibres used as concrete admixtures for improving its mechanical properties. Plasma treatment was conducted in low-temperature plasma at atmospheric pressure. Dielectric barrier discharges in both coplanar and volume configuration of electrodes were used for this purpose. The degree of hydrophilicity caused by plasma treatment was determined by measuring the rate of penetration of liquids into the porous media, so called Washburn method. The optimized plasma treatment of industrially used polypropylene fibres ensured further 20% surface wettability improvement comparing to the standard chemical treatment.