During complex loading, bending moments within the cervical spine are frequently calculated at the center of rotation (COR) for a particular joint. The COR location is often inexact as it is described by an anatomical feature whose location is poorly identified using conventional imaging or superficial anatomic landmarks. The most important example is the use of the occipital condyles as the COR and reference landmark for flexion and extension bending moment within the upper cervical spine and in anthropomorphic testing devices (ATDs). Although upper cervical neck moments are calculated about the occipital condyles, the condyles and the COR for the human upper cervical spine have not been quantitatively located, particularly with respect to other known cranial landmarks. In this study, ten upper cervical spine specimens were tested in both flexion and extension at pure moment increments of approximately 0.5 N-m to determine CORs of the upper cervical spine. Using digital images recorded at each moment increment, the location of tracking markers attached to the C1 and C2 vertebrae were determined. These marker locations were used to determine the CORs for O-C2 and O-C1 motion segments using Reuleaux's method (Panjabi et al., 1982). Following the biomechanical testing, cranial landmarks, including the occipital condyles, were identified and digitized in 3D-space using a MicroScribe 3Dx with Immersion Inscribe3 software. Other landmarks digitized included the external auditory meatus, infraorbital foramen, zygion, nasion, foramen magnum, and the Frankfort plane. For each specimen, motion segment COR and head center of gravity (CG) were plotted on a reference digital image and the digitized cranial landmarks were registered and plotted on the same image. Preliminary results showed the CORs of O-C1 for a majority of the specimens were superior to the condyles and the O-C2 CORs were inferior to the condyles in flexion. The CORs of O-C1 were anterior to the CORs of O-C2 in both flexion and extension. This approach allowed qualitative and quantitative comparison between the upper cervical spine COR and commonly referenced cranial landmarks.