A gas bag arrangement for a vehicle occupant restraint system is provided. The gas bag arrangement comprises a gas bag inflatable by a gas generator to protect a vehicle occupant, whose envelope defines an interior space of the gas bag that can be filled with gas, a vent opening through which gas can flow out of the gas bag, and a device for controlling the outlet cross-section of the vent opening, which comprises at least one covering part with which the vent opening can be covered, in order to at least partly close the same, and which furthermore comprises an actuating mechanism which interacts with the covering part, in order to vary the outlet cross-section of the vent opening. The actuating mechanism includes an additional gas source and an element different from the gas bag and inflatable by means of the gas source.