Abstract: Diffuse gliomas are brain tumors that develop from glial cells and are notable for being very invasive and difficult to eradicate. Getting the right diagnosis of diffuse gliomas is critical for proper therapy and prognosis. Significant progress has been made in histopathologic and molecular approaches for identifying diffuse gliomas in recent years. In this study, it provides an overview of the most recent histopathologic and molecular methods used to diagnose diffuse gliomas, including immunohistochemistry, next-generation sequencing, fluorescence in situ hybridization, and DNA methylation profiling. The advantages and limitations of each technique are to be discussed to provide recommendations for the optimal approach to diagnosis in different clinical scenarios.