The rotator cuff exercise device includes a ring unit, a mounting board, and a pair of mounting tracks. The rotator cuff exercise device may be adapted to exercise joints and muscles or may prevent the loss of flexibility in an elbow or a shoulder blade. The rotator cuff exercise device may be particularly suited for therapy after an injury involving a rotator cuff. A handle may detachably couple to an individual rotatable ring selected from one or more rotatable rings of the ring unit and may be adapted to be grasped by a hand of the user. The handle may be operable to move the individual rotatable ring in a circular motion. The circular motion of the handle may exercise the joints and muscles of the user.