A method for folding an airbag includes folding the airbag into an elongate state at least partially by roll-folding. The method also includes inserting a gas generator and/or an airbag-retaining metal sheet into the airbag. The gas generator and/or the airbag-retaining metal sheet is/are located in the central third of the airbag folded in elongate shape so that two end portions of the airbag project from the gas generator and/or from the airbag-retaining metal sheet. The method also includes guiding the airbag end portions around the outer circumference of the gas generator and/or of the airbag-retaining metal sheet in opposite directions toward each other up to a folding zone in which the end portions of the airbag at least almost contact each other. The method further includes folding over the end portions of the airbag from the folding zone outwards and guiding the airbag end portions in the opposite direction around the outer circumference of the gas generator and/or of the airbag-retaining metal sheet and around internal parts of the airbag end portions located thereon for forming external parts.