An apparatus and a method for reducing power consumption of an Application Processor (AP) in an electronic device are provided. The electronic device includes a first processor for supporting a first Internet Protocol (IP) Multimedia Subsystem (IMS) protocol stack, and a second processor for supporting a second IMS protocol stack. The first processor includes an AP for processing a multimedia service, and the second processor includes at least one of a Communication Processor (CP), a Modem Processor (MP), and a Baseband Processor (BP) for processing a communication service.