Face-centered cubic (fcc) nickel nanoplatelets with hexagonal and triangular shapes were created by a simple one-step ethylene glycol reduction method under alkali medium without any surfactants. A series of contrast experiments revealed that the alkali concentration played a key role for the formation of the anisotropic nickel nanocrystals with defined shapes. Thus-prepared nickel nanoplatelets exhibited a ferromagnetic characteristic with a coercivity of 224.2 Oe.