An adjustable forehead support for a nasal mask. The present invention discloses an adjustable forehead support for a nasal or full-face mask wherein the forehead support may be adjusted for the different shapes and sizes of a facial profile. The forehead support utilizes a dual-arm system which adjusts the position of the forehead support vis-à-vis the mask and/or air flow tube. The angle of the mask to the face may be adjusted with the present invention.