Aim:The aim of this study was to investigate the effects of methylphenidate (MPH), which has psychostimulant effects, on intervertebral disc tissue (IVD) cell cultures and extracellular matrix structures. Changes in the expression of some important marker genes involved in anabolic and catabolic mechanisms of IVD extracellular matrix formation were also investigated.Material and Methods:Primary cultures of nucleus pulposus cells (NPCs) and annulus fibrosus cells (AFCs) were isolated from tissues obtained from the operated patients. Cell viability and proliferation were tested, and the cell surface morphologies were evaluated by microscopy. The expressions of the chondroadherin (CHAD), cartilage oligomeric matrix protein (COMP), interleukin-1 beta (IL-1β) and matrix metalloproteinase (MMP) -7 and MMP-19 genes were evaluated using the quantitative real-time polymerase chain reaction (qRT-PCR). A value of P <0.05 was considered statistically significant.Results:The viability and proliferation of intervertebral disc tissue cells decreased in response to MPH treatment and the expression of the investigated genes also changed.Conclusion:The data obtained from in-vitro studies may not directly adaptable to clinical applications. However, the fact that the central nervous system stimulant MPH can suppress proliferation of cells derived from IVD tissue should be considered carefully by clinicians.