Cobalt is principally produced by hydrometallurgical means from the copper-cobalt ores of Zambia and Zaire. In addition cobalt is commonly found in minor quantities in association with nickel and copper-nickel orebodies. Generally the level of cobalt common to these latter orebodies does not warrant separate processing unless the metal price reaches levels last achieved in 1979 and 1980. For pyrometallurgical processing the distribution of cobalt and the factors which affect the distribution of cobalt between matte and slag are not well understood. A limited amount of fundamental research has been completed on cobalt distribution both for simple oxide and matte systems. The paper briefly reviews the relevant literature on theoretical aspects of cobalt distribution between metal and slag and the deportment of cobalt in sulphide smelting circuits. The deportment of cobalt in the Kalgoorlie Nickel Smelter circuit is critically analysed and areas where recovery improvements may be achieved are highlighted.