To date, there have been no reports of experiments demonstrating the effects of neodymium:YAG laser (Nd:YAG laser) on the vertebral end-plates. In this study the effect of Nd:YAG laser on end-plates was examined in 32 guinea pigs which were randomly divided into two groups. The first group was the control group, the second one the Nd:YAG laser group. All animals had experimental disc degeneration at three levels. Re-exploration was performed two months after the surgical ventral disc herniation. In the second group the same procedure was performed but at the end of the re-exploration, Nd:YAG laser irradiation of the degenerated discs was done. The wounds in both groups were closed again. Two months later all animals were sacrificed for histological and biochemical analysis. The cervical spine was excised en bloc and the overlying muscles were removed. Determination of hydroxyproline was done colorimetrically in the specimens harvested from each of these groups. Light microscopy was undertaken to evaluate the extent of morphological changes. The differences observed between the two groups were statistically significant (p < 0.05). From the results of this study, there is the question whether the Nd:YAG laser is a useful instrument in neurosurgery. Therefore, it remains to be proven whether or not this is of real benefit in the treatment of patients with degenerated disc disease.