A remote controller (100) and a system and method for remotely controlling a digital TV are disclosed. A memory card (110) is mounted in the remote controller (100), and the remote controller (100) receives video or audio data inputted from the memory card (110) and transmits the received data to a TV body (300). The remote controller (100) receives the video or audio data from the memory card (110) modulates the received data into a wireless signal and transmits the modulated wireless signal, and the TV body (300) receives the wireless signal transmitted from the remote controller (100), demodulates the received wireless signal into the video or audio data and reproduces the demodulated video or audio data. Therefore, the user can remotely control the TV body (300) without personally inserting the memory card (110) into the TV body (300). As a result, the user does not need to move to a place where the TV body (300) is located resulting in convenience in use.