A method of folding or compacting a door-mounted inflatable curtain airbag to reduce the overall length of the airbag for positioning onto a vehicle. The airbag may generally be substantially parallellogrammatical in shape. The method involves a two-step process (1) folding the airbag along an axis that is substantially normal to the rear edge (first edge) of the airbag and (2) subsequently folding the airbag radially to compact the airbag down into its final, storable position. The present methods allow folding, compaction of the airbag without having a fold that is parallel to the compacted length of the airbag.