A description and most recent validation of PASSIMPLUS, a multi-element passenger side airbag model for analyzing airbags of complex shape, is discussed. This model has the capability of simulating passenger interaction with a three dimensional airbag of completely arbitrary, user defined shape. Further, this model actually simulates the instantaneous shape of the airbag as determined by the various contact surfaces encountered by the airbag. Therefore, the shape of the contact surface presented to the passenger is not constant and can accommodate large deflection penetrations by the passenger. Because of the multi-element airbag approach, the effect of instantaneous vent blockages on porous airbag materials may be evaluated. Up to 3000 airbag elements can be used to configure the desired airbag geometry. Airbag mass and its effect on airbag deployment rate and the subsequent bagslap forces are computed. Because of this, the model is capable of simulating forward positioned children as well as normally seated adults. The model is fully supported by various menu driven pre- and post processors for creating the input files as well as evaluating the output. A special, menu driven, interactive pre-processor structured to receive User input in a format compatible with conventional airbag drawing coordinates and dimensions facilitates rapid creation of the 3-D airbag “mesh.” Because of this, the multi-element mesh, for even the most complex airbag shapes, may be quickly obtained. Another pre-processor computes the inflator mass flow and gas temperatures from tank test data. All FMVSS-208 injury measures are computed and summarized. Post-processors provide full graphic output in curve overlay (for comparing test vs. simulation or simulation vs another simulation) and kinematic format. The most recent validation of the model is discussed. This validation situation involves a normally seated, adult passenger. The results show that the model is not only easy to use but also very accurate in its predictive ability.