An image display system may include an image display device, and first and second attachments. The image display device may include a frame wearable on a user's face, a display unit, display controlling unit causing the display unit to display an image, and a joint portion provided on the frame, capable of having the first attachment mounted thereon, capable of having the second attachment mounted thereon, and capable of selectively having one of the first and second attachments mounted thereon when the image display device is used. The first attachment may include an engaging portion capable of engaging with a use's head and a first attaching portion that attaches the engaging portion to the joint portion. The second attachment may include a fixing portion fixable to headwear covering the user's head and a second attaching portion that attaches the fixing portion to the joint portion.