Abstract: An airbag for a vehicle occupant restraining system of a motor vehicle is provided. The airbag comprises a pre-folded portion, which comprises at least two subsections of the airbag, of which the one subsection is folded about a folding line via bend folding to an inner side of the other subsection facing the vehicle interior space in the mounted and inflated status of the airbag. The folded subsection is formed such that it extends in the mounted and inflated status of the airbag beyond a door balustrade of a vehicle longitudinal side. The airbag further comprises a roll folded portion, which comprises the pre-folded portion, wherein the roll folded portion is formed by rolling up the airbag to an outer side of the airbag facing in the mounted and inflated status of the airbag a vehicle longitudinal side.