Iron nanoparticles with a diameter of 35 nm are synthesized by the thermal decomposition of iron pentacarbonyl in a hot wall reactor. The particles are ferromagnetic and single magnetic domain. The magnetic forces between the particles cause the formation of iron nanowires of up to 300 µm in length. Morphological characterization using high resolution transmission electron microscopy indicates an oxidic shell with a thickness of 3–4 nm. The electrical properties of single chains are investigated under air using impedance spectroscopy (IS). It is found that the conductivity of the iron is in the same range as that of the bulk material. Temperature dependent measurements on iron nanochain powders performed under H2-atmosphere reveal strong sintering effects and a transition into iron.