The present invention relates to an impeller assembly for centrifugal pumps, comprising a first disk-like element, operatively arranged towards a coaxial inlet, facing a second disk-like element with a smaller diameter, operatively arranged towards the outlet; this second disk-like element is rigidly connected to the first disk-like element through a set of angularly spaced blades, and is centrally provided with fastening means for fastening to a drive shaft. The distinctive feature of the present invention is that the blades comprise appendices, in flat sheet form, adjacent to the second disk-like element, which are essentially located in correspondence with areas subject to lesser axial thrust.