Iron sulfide (Fe1-xS, x=0-0.125) nanostructures are synthesized via a thermal decomposition method using iron oleate and alkylthiol as precursors. It is shown that nanoflower, hexagonal nanoplates or nanorod structures can be obtained by optimizing the precursor ratio and choosing an appropriate high b.p. organic solvent. The results show that the precursors, iron oleate and alkythiol, react to form a single source precursor, iron alkylthiolate, which prompts the formation of Fe-S bonds. The electrondiffraction analyses suggest that the products have predominantly a 3C-type pyrrhotite superstructure. The characterization results indicate that the unique morphologies of the different Fe-S nanostructures are the consequence of a temperature-dependent oriented attachment growth mechanism. Published by Elsevier B.V.