This article is the first of 2 parts. Cervical artificial disc replacement represents an exciting new frontier in spine surgery for degenerative cervical disease. This article reviews the history, development, and biomechanics of the cervical artificial disc. An analytical comparison of the currently available arthroplasty systems is also presented. Cervical disc arthroplasty focuses on preserving motion at the treated level while minimally affecting motion in the adjacent levels. The postulated advantage of this approach is a reduction in adjacent level degenerative disease. However, more comprehensive biomechanical data are needed before arthroplasty devices are widely accepted and implanted. Computational analysis of cervical spine load transmission will enhance the available knowledge and facilitate the design of the next generation of prostheses.