Magnetic cobalt/nickel nanowires with high coercivity at room temperature have been prepared by reduction in liquid polyol using heterogeneous nucleation. Anisotropic growth is controlled by a high number of ruthenium seeds and an appropriate sodium hydroxide concentration. Growth occurs preferentially along the c-axis for low sodium hydroxide concentrations, giving wires (see Figure), and platelets perpendicular to the c-axis at high concentrations.