The magnetotransport properties of current perpendicular to the plane giant magnetoresistive spin-valves utilizing (CoFe)(100-x)Ge(x) alloys are investigated. The composition range of 21 <= x <= 32 at. % is determined to be the alloy composition that maximizes magnetoresistance. Delta RA values of 2.6 m Omega-mu m(2) are measured for spin-valves with CoFeGe in the free and reference layer resulting in magnetoresistance values of greater than 6%, which is almost twice the value of similar spin-valves with CoFeAl alloys. An analysis of the physical properties of the CoFeGe thin films in the range of interest is also presented. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2993213]