Nano-sized nickel sulfides were synthesized by the thermolysis of nickel alkanethiolates in the presence of coordinating ligands. Nickel alkanethiolates were synthesized by the reaction of the square planar nickel 1-dimethylamino-2-methyl-2-propanolate [Ni(dmamp)2] with various n-alkanethiols. The effect of ligands in the reaction system has been investigated to control the size and shape of nano-sized nickel sulfides. TEM images show that the products are nano-sized nickel sulfides in rod and plate shapes. Nickel alkanethiolates and nano-sized nickel sulfides have been characterized by means of X-ray diffraction and transmission electron microscopy.