Thick cobalt coatings (10-40 mum) with a range of morphology and structure were obtained by electrodeposition on both vitreous carbon and copper electrodes. There is a direct relation between the morphology, structure and magnetic properties of cobalt deposits. A chloride medium at pH 4 and low deposition rates favoured the formation of black, ridge-like deposits of hexagonal close packed (h.c.p.) structure with mixed (100) + (110) preferred orientations. In CoCl2 at pH 4 at current densities in excess of -80 mA cm(-2) and in CoSO4, dull grey deposits of h.c.p. (110) structure formed. Sulfate + citrate and chloride + citrate baths at pH 1.5 and very negative current densities promoted the formation of metallic grey deposits with face centred cubic (f.c.c.) structure. Constant saturation magnetization (M-s) was obtained for cobalt deposits independently of their structure (M-s = 160 emu g(-1)) although the coercive field (H-c) of the material varied: h.c.p. (100) > h.c.p. (110) > f.c.c.