Abstract: The invention provides a process for preparing a sterile suspension comprising aripiprazole. More particularly, the invention provides the process for preparing the sterile suspension comprising aripiprazole, wherein said process involves in-process moist-heat sterilization of said suspension comprising aripiprazole. The in-process moist-heat sterilization is particularly efficient and economical process for the sterilization of aripiprazole formulations for parenteral administration, wherein the formulation obtained by said process have comparable physicochemical characteristics with the commercially available Ability Maintena® Injection.