Mortality after gluteal augmentation with fat transfer techniques is extremely high. Placement of fat subcutaneously versus in the gluteal musculature, or both, is considerably debated. The purpose of this study was to radiographically show the anatomical difference in live subjects in different procedural positions: the flexed or “jackknife” versus prone position. A total of 10 women underwent computed tomographic scanning of the pelvis with venous phase run-off in both the jackknife and prone positions. A computed tomography–specialized radiologist then reviewed images and measured distances from the inferior and superior gluteal veins to the skin and muscle. Three-dimensional imaging and analysis were also performed. Measurements were significantly shorter with respect to distance from skin to muscle, skin to vessel, and vessel to muscle observed from inferior and superior gluteal veins in the jackknife versus the prone position. Three-dimensional modeling showed a significant reduction in the volume and inferior and superior gluteal vein diameters when in the jackknife position. When placed in the jackknife position for gluteal augmentation with fat transfer, extreme caution should be taken with the injecting cannula, as the underlying muscle is only 2 to 3 cm deep. Three-dimensional analysis showed narrowed and reduced volume of gluteal vasculature when in the jackknife position; this is a possible indication of torsion or stretch on the vessel around the pelvic rim that could cause vein avulsion injury from the pressurized fat within the piriform space.