Boron carbide whiskers and platelets have been synthesised via a carbothermal vapour-liquid solid (VLS) growth mechanism starting with B2O3 and carbon black as sources of boron and carbon, respectively. The reactions were studied in the temperature range 1200-1800degreesC. testing Co, Ni and Fe as catalyst metals. The best result was obtained at a synthesis temperature of 1700degreesC with a reaction mixture containing B2O3:C:NaCl:Co in the molar ratios of 1:6:0 25:0.1. The obtained boron carbide product exhibited different morphologies ranging From elongated platelets to whiskers with very high aspect ratio. Five different whisker-like crystal morphologies were found, and their growth directions and structural defects were characterised by means of transmission electron microscopy. (C) 2002 Elsevier Science B.V. All rights reserved.