Abstract <p>Brain tumors account for approximately 2.5% of all tumor-related deaths worldwide. Despite significant advances in cancer diagnosis and therapy, the treatment of brain tumors remains challenging, mainly due to limitations in effective drug delivery to tumor tissue. One of the major obstacles is the blood–brain barrier, which restricts the penetration of many therapeutic agents into the brain. Nanoparticle-based drug delivery systems have emerged as a promising strategy to overcome this barrier and deliver sufficient concentrations of therapeutic agents directly to cancer cells. This review is based on an extensive literature search conducted in PubMed, Google Scholar, and Web of Science using relevant keywords, covering articles published between 2001 and 2025. Numerous studies have investigated the application of nanoparticles in the treatment of incurable diseases, including various types of cancer. Nanoparticles can be broadly classified into inorganic, lipid-based, and polymeric systems. Precise control of nanomaterial size, weight, and surface properties is crucial for targeted design according to tumor type. Research indicates that carbon-based nanomaterials are effective drug delivery platforms due to their strength and high drug-loading capacity. Lipid nanoparticles have demonstrated potential as carriers for chemotherapeutic agents and gene delivery because of their ability to encapsulate and control drug release. In addition, studies show that mesenchymal stem cells can transport drug-loaded nanoparticles to brain tumors such as gliomas and inhibit tumor growth. Overall, properly designed drug- and gene-carrying nanoparticles represent a promising therapeutic approach for brain tumor treatment; however, further studies are required to ensure safety and clinical applicability.</p>