It is a yellow-green solid. It dissolves in water. It normally is attached to water molecules (hydrated). It reacts with ammonia to make a purple solution. It also reacts with hydrochloric acid to make a yellow solution. It reacts with bases to make nickel(II) hydroxide. Solutions of nickel(II) chloride have a pH of 4.
Nickel(II) chloride irritates skin and eyes. It can also cause cancer.