High-speed biplane x-ray was used to investigate relative kinematics of the thoracoabdominal organs in response to blunt loading. Four post-mortem human surrogates instrumented with radiopaque markers were subjected to eight crash-specific loading scenarios, including frontal chest and abdominal impacts, as well as driver-shoulder seatbelt loading. Testing was conducted with each surrogate perfused, ventilated, and positioned in an inverted, fixed-back configuration. Displacement of radiopaque markers recorded with high-speed x-ray in two perspectives was tracked using motion analysis software and projected into calibrated three-dimensional coordinates. Internal organ kinematics in response to blunt impact were quantified for the pericardium, lungs, diaphragm, liver, spleen, stomach, mesentery, and bony structures. These data can be used to better understand the interaction of anatomical structures during impact and the associated injury mechanisms, and for the development or validation of human body finite element models.