A protective instrument cover includes at least a front portion that extends over substantially an entire front surface of an instrument body of, for example, a guitar, and preferably also includes a side portion and a back portion that cover the side and back surfaces of the instrument, respectively. The cover is preferably made, at least partially, of stretchable material. A fastener such as a zipper attaches the cover to the instrument body. The cover preferably can be attached to the instrument body without requiring removal of hardware of the instrument body.