The most nontrivial components of dynamic systems are the rods. For the flexibility of the spine, it is necessary to combine dynamic screws with flexible rods to maintain the motion of a vertebral segment. On the other hand, in order to achieve a good fusion, a constant load is necessary on the intervertebral graft. To achieve this ideal objective, the design and material of a dynamic rod must be perfect. Composition should be biocompatible and tough enough for lifelong movement. Unfortunately, there is currently no such instrument in the market. In our clinical experience of dynamic systems, we have used most of the dynamic rods (Graf ligament, Talin, Dream, Agile, BalanC™, Flex+2, and BioFlex) and tether systems. So we have witnessed the pros and cons of these systems. We present our experiences with dynamic rods, based upon about 30 years of motion-preserving surgery history, in the light of the literature and our clinical background.