In this paper the effect of varying temperature, pressure and chemical precursors on the vapour-liquid-solid (VLS) growth of silicon nanowires (Si NWs) have been investigated. Some aspects of nucleation and growth mechanisms are discussed. Control on Si NW morphology by varying the choice of gaseous precursor (silane or dichlorosilane) at elevated temperatures is reported. © 2008 Springer Science+Business Media B.V.