Nanocrystalline Cobalt is one of the most important magnetic material due to the phase-dependent magnetic properties exhibited by its allotropic phases. The anisotropic high-coercivity hcp-Co phase is preferred for permanent magnet applications, while the more symmetric low coercivity fcc- and ε-CO can be used in soft magnetic applications involving power electronics and magnetic write heads. The present work addresses the synthesis and characterization of nanocrystalline cobalt particles produced through a modified polyol-based approach conducive to the formation of fcc-, hep-, ε-Co, or mixtures of fcc/hcp-Co phases. Magnetic measurements confirmed the strong influence of synthesis conditions on crystal structure and hence, on magnetic properties of nanocrystalline cobalt. The coercivity of the products varied from 148 Oe to 778 Oe depending on the presence of the different cobalt structures.