Gliomas are the most common malignant brain tumors, which are often associated with high-grade tumors characterized by an inferior prognosis and low patient survival rates in both children and adults. Surgical removal and tumor resection are the primary treatment approaches for gliomas. In such cases, whole-brain radiation therapy is also employed as a therapeutic option, which itself has significant side effects, and studies have shown limited impact on improving patient survival. Targeted therapy and recently investigated approaches such as targeted therapy have shown some tumor regression, but in most cases, tumor recurrence has been observed after initial regression. Therefore, they have a limited impact on prolonging patient survival. Immunotherapy, particularly immunotherapy with specific immune cells, can effectively identify and eliminate cancer cells and has been utilized as a new approach in the past two decades, especially in cancers where conventional methods have limited success. Among the effective immunotherapy methods, using natural killer cells (NK cells) can be one of the promising approaches. Currently, phase I clinical trials have been conducted by our research group in patients with gliomas.