An apparatus and a method for reducing power consumption using packet filtering in a portable terminal are provided to allow a modem to filter a packet in order to prevent an Application Processor (AP) from waking up from a sleep mode due to an unnecessary packet. The portable terminal includes an AP for providing a list of packets required in the AP itself to a packet determiner, and the packet determiner for filtering a packet included in the list provided from the AP and for providing the packet included in the list to the AP.