The aim of this study is the synthesis of nanoscale, nonagglomerated, and redispersible Co-3[Co(CN)(6)](2) nanoparticles via a microemulsion approach. Furthermore, the micellar system is heated to reflux to enhance materials crystallinity. Crystallinity, chemical composition, and optical and thermal properties of the title compound are investigated in detail. SEM, XRD, and DLS measurements evidence an average diameter of 25-30 nm of the as-prepared nanocrystals as well as of powder samples subsequent to centrifugation, washing, drying, and resuspension. Based on IR and UV-vis spectra, the anhydrous character of Co-3[Co(CN)(6)](2) is validated. The thermal decomposition of Co-3[Co(CN)(6)](2) results in the formation of Co3O4, which is still nanoscaled.