In this paper the rationale for total disc replacement is discussed, and the authors suggest seven requirements that should be met before the implantation of these devices can be accepted as regular procedures. In an attempt to answer the questions raised, a systematic literature search was performed. The search yielded no controlled trials and nine case series with a total of 564 arthroplasties in 411 patients. The devices used were SB Charité in eight and Acroflex in one study. The percentage results classified as "good" or "excellent" in the studies varied from 50 to 81%. Complications were observed in 3-50% of the patients. Twenty-two of the operated levels were fused either spontaneously or after additional surgery. A meta-analysis to compare the results with other treatments could not be performed due to the lack of comparative studies. Despite the fact that these devices have been implanted for almost 15 years, on the basis of this literature survey there are currently insufficient data to assess the performance of total disc replacement adequately. There is no evidence that disc replacement reliably, reproducibly, and over longer periods of time fulfils the three primary aims of clinical efficacy, continued motion, and few adjacent segment degenerative problems. Total disc replacement seems to be associated with a high rate of re-operations, and the potential problems that may occur with longer follow-up have not been addressed. Therefore, total disc replacements should be considered experimental procedures and should only be used in strict clinical trials.