The surface tension of liquid binary alloys of the Cu-Ni-Fe system is measured by using the oscillating drop technique. The samples are processed contactlessly in an electromagnetic levitation chamber and hence, considerably large undercooling can be achieved. The alloys and the pure elements copper, nickel, and iron are investigated at various temperatures above and below their melting points. In addition, the surface tensions are also investigated as a function of the concentrations at constant temperature. The values agree well with predictions from theory and an analysis of the segregational behaviour is performed. (C) 2005 Springer Science + Business Media, Inc.