Abstract: A vehicle occupant restraint system (10) comprises a vehicle seat (12) including a backrest (14) with a seat back surface (24), wherein the seat back surface (24) is provided for a vehicle occupant seated in the vehicle seat (12) to lean there against, and comprises an airbag module (16) integrated in the vehicle seat (12) which includes an airbag (18) being L-shaped in a horizontal section plane. The airbag (18) has a fillable cushioning portion (20) forming a first leg of the L which is positioned along a seat longitudinal direction (L) spaced from the seat back surface (24), and a fillable connecting portion (22) forming a second leg of the L which connects the cushioning portion (20) to the vehicle seat (12).