Magnetic resonance imaging (MRI) is being applied successfully to the study of the musculoskeletal system with notable recent advances, including the use of three-dimensional imaging techniques. The authors introduce three-dimensional MRI as a technique for examining proximal femoral anatomy and suggest its use as an improvement on current methods for prosthetic hip design. The proximal femurs of 14 cadavers were scanned using a three-dimensional FISP technique and the images were subsequently manipulated on a three-dimensional MRI image-processing workstation to produce rotated surface reconstructions and multiplanar reformatted images. The surface rotations showed that the marrow cavity contours closely follow the contours of the external cortex. Axially reformatted images allowed relative area measurements of the marrow cavity, quantifying the variability between subjects.