Fe(x)Pt(100-x) nanoparticles of varying composition have been synthesized with various shapes and sizes using a high pressure synthesis method which allows control of synthesis conditions, in particular the reaction temperature. Tailoring the shapes and sizes of Fe(x)Pt(1-x) nanoparticles allows one to control a variety of properties that are relevant to the many potential applications of metallic nanoparticles. Shape and composition can be used to control catalytic activity and to achieve high packing density in self-assembled films. Variation of both nanoparticle size and shape has been achieved by using various different solvents. The solvents used in the nanoparticle synthesis can influence the product because they can play a role as surfactants. Using solvents of various types it has been possible to synthesize Fe(x)Pt(100-x) nanoparticles with a variety of shapes including spherical, rod-like, cubic, hexagonal and high aspect ratio wires. Control of nanoparticle shape opens the door to their being used in various technological applications for which spherical nanoparticles are ineffective.