A controlled release sterile freeze-dried aripiprazole formulation is provided which is formed of aripiprazole of a desired mean particle size and a vehicle therefor, which upon constitution with water and intramuscular injection releases aripiprazole over a period of at least about one week and up to about eight weeks. A method for preparing the controlled release freeze-dried aripiprazole formulation, and a method for treating schizophrenia employing the above formulation are also provided.
