The HDMI cable is already included with the cable box. But, you will need another HDMI cable, if you jump from Box, to Receiver, to TV. If you run the HDMI cable directly to the TV, you will need a Optical Cable to run from the cable box to the receiver, if you want sound from the receiver. If you run HDMI from BOX to RECEIVER to TV, that HDMI Cable is all you need, for both picture and sound. Sorry the the 'ring around the rosy'.