Abstract: A protective device for gas cylinders is provided that protects the body of the gas cylinder from damage, is light, does not affect the required heat exchange from the environment to the liquified gas within the gas cylinder and renders the gas cylinder assembly easier to stack for safe storage. The protective device in accordance with the principles of the invention comprises a top part and a bottom part forming a cavity within which the gas cylinder is placed. In accordance with an illustrative embodiment of the invention, the top part and bottom part are both made of synthetic materials and are interconnected during assembling process by a standard functional clipping device. These clippings may be broken in order for the protective device to be removed, allowing visual inspection of the gas cylinder without damaging the gas cylinder in the removal process.