Metastable greigite (Fe3S4) nanocrystallites with different morphologies have been selectively fabricated via a simple solution-based route. The influence of reaction temperature on the formation of iron sulfides is studied and it is found that the reaction temperature play key role in the preparation of pure Fe3S4 nanocrystallites. Based on the investigation of the magnetic properties of the products, it reveals that the morphology of the products have important influence on the magnetic properties. (C) 2005 Elsevier B.V. All rights reserved.