An airbag jacket, to be fitted in a rider jacket, includes an airbag body configured to fill with gas from an inflator operatively connected with the airbag body. The airbag body includes a flat front piece, a flat back piece substantially identical to the flat front piece; the flat front and back pieces having an opening formed therein for permitting an user of the airbag jacket to pass his or her head therethrough. The flat front and back pieces are joined together along a peripheral boundary thereof and along a peripheral boundary of the opening by sewing or bonding so as provide a plurality of continuously formed body covering portions including at least a back covering portion, a shoulder covering portion and a front covering portion.