An object of the present invention is to provide a freeze-dried aripiprazole powder formulation that exhibits good dispersibility and is easily dispersed into a homogenous suspension when reconstituted with water. The present invention provides a freeze-dried aripiprazole formulation obtained by a process comprising the steps of spraying for freezing an aripiprazole suspension containing (I) aripiprazole, (II) a vehicle for the aripiprazole, and (III) water for injection, and drying