A general and facile method is reported for the synthesis of a wide range of metal sulfide nanocrystals including silver sulfide, zinc sulfide, cadmium sulfide, lead sulfide, bismuth sulfide, tin sulfide, iron sulfide and copper sulfide, etc. This method is based on the thermal decomposition of single-source precursors composed of metal-diethyldithiocarbamate in solution phase. By this method, not only the size and shape but also the chemical composition of the products can be easily controlled. Furthermore, these as-synthesized metal sulfides with different sizes, shapes and chemical compositions exhibit novel optical, electronic and magnetic properties, such as near-infrared (NIR) photoluminescence (PL), strong ferromagnetism and excellent electrochemical properties. We expect that this facile methodology for metal sulfides synthesis can be generalized to other nanocrystals synthesis, and be of high importance to explore the new properties.