The controlled production of arrays of nanowires exhibiting outstanding characteristics is recently attracting much interest owing to their applications in a number of emerging technologies related with multifunctional biosensor applications, controlled optomagnetic response, magnetic storage, magnetotransport, or catalytic performance. [1±3] While nanolitography methodes require sophisticated experimental facilities, an alternative technique that makes use of much simpler conventional anodization and electrodeposition methods in the fabrication of metallic nanowires arrays is increasingly employed. This method allows the preparation of arrays of highly-ordered nanopores induced by anodisation, and its filling with metallic elements by electrodepositon. This is certainly a quite versatile and nearly inexpensive technique to fabricate nanoscaled arrays with systematically reproducible properties. [4] A number of novel materials with new and optimised properties can be envisaged thanks to the capability of playing with the nature of the nanowires, magnetic or not, and that of the embedding matrix, metallic, semiconducting or insulating, which can be tailored by suitable replica-antireplica processes. For example, in the case of composite magnetic materials, new phenomena and interactions can be studied in ideally ordered nanomagnets embedded into magnetic/non magnetic matrices.The final objective of the research presented in this work is the fabrication of arrays of magnetic nanowires with high packing density and controlled magnetic anisotropy. Ideally, individual nanowires should keep its own magnetic identity and consequently, give rise to individualized response under the action of external magnetic field. It means, for example, that macroscopic hysteresis loops of the arrays should exhibit high remanence to saturation magnetization ratio and large coercivity, in the order units of kOe. Two factors determine the magnetic response of the nanowire arrays: i) The symmetry and the characteristics of the geometrical arrangement of the nanopore/nanowire array, which determines the strength of the magnetostatic interaction among neighbouring nanowires [5] , and ii) The magnetic nature of individual nanowires, which determines the strength of their magnetic anisotropy (see for example studies on the magnetic behaviour of nanowire arrays of metallic elements as Ni, Fe and Co in [6] ).An important goal is the determination in each case of the magnetic anisotropy of individual nanowires. The first contribution to be considered in wires is naturally that of the shape, which induces a uniaxial magnetic anisotropy with easy axis of magnetization parallel to the nanowire axis. Typically, Ni or Fe nanowires with sufficiently large length to diameter ratio, exhibit longitudinal magnetization easy axis determined by their shape anisotropy which overcomes magnetocrystalline and magnetoelastic contributions. To put some numbers, for example Ni nanowires present a crystal anisotropy constant (with cubic crystalline structure growt...