A flexible cushion system for oxygen mask comprises an oxygen mask for providing oxygen gas from a gas source to a user to breathe in the gas through the users nose. A cushion is provided for connecting to the mask for protecting and comforting the users face. In one embodiment, the cushion comprises a nasal bridge section for connecting to a mask section that places on wearers nose, a cheek section for connecting to a mask section that places on wearers cheek, and a chin section for connecting to a mask section that places on wearers chin. In one embodiment the cheek section and the chin section are separate pieces. Preferably, each of the nasal bridge section, the cheek section and the chin section are separable from the mask. In another embodiment the cushion is in one piece. Preferably, the cushion thickness can be reduced from an initial thickness by one or more perforations along its original surface.