A guide device for sliding doors for shelves has at least one guide rail, each guide rail have a guide region for guiding sliding doors and at least one fastening region connected to the guide region for fastening the guide device to shelves. The guide regions in their cooperation form a guide arrangement and all the fastening regions in their cooperation form a fastening arrangement. In order to provide a guide device which can be used universally and which can be fastened subsequently to shelves, the fastening arrangement is disposed relative to the guide arrangement in the installed position in such a manner that the guide arrangement is accessible from below and above for sliding doors and at least partially covers vertical surfaces of the shelves.