Molecular chaperones, especially Heat Shock Proteins (HSPs), play complex, context-dependent roles in cancer, particularly in nervous system (NS) tumors like glioblastoma (GBM) and neuroblastoma (NB). They are often upregulated, promoting tumor growth, poor prognosis, and resistance to therapy and immune responses. This supports the potential of negative chaperonotherapy, aimed at inhibiting them. However, some studies suggest chaperones can also act as tumor suppressors in certain cancers, indicating that positive chaperonotherapy—enhancing or restoring their function—may be beneficial. For NS tumors, this latter area is still understudied. With emphasis on GBM and NB, in this review we address the potential of molecular chaperones, particularly HSPs, as therapeutic targets or agents. We discuss strategies to inhibit pro-tumorigenic chaperones as well as the underexplored potential of chaperone induction and immunomodulation. Ultimately, we examine the emerging use of pharmacological and chemical chaperones to improve treatment outcomes in these NS tumors. These strategies, whether applied alone or in combination, may offer significant benefits for GBM and NB, which are presently among the most aggressive and challenging tumors to manage.