This review provides an overview of epidemiological studies on primary brain tumors, aiming to encourage multidisciplinary research among surgeons, neuro-oncologists, epidemiologists, and molecular scientists. The review highlights the importance of understanding the causes of brain tumors, given their poor prognosis and the recent progress in molecular classification. It discusses the challenges in interpreting time trends in incidence and mortality, the role of geographic and ethnic variations, and the significance of survival and prognostic factors. The review also examines hereditary syndromes, polymorphisms in genes related to carcinogenesis, and noninherited endogenous, infectious, and environmental risk factors. While some factors like inherited mutations in TP53 and p53 have been linked to brain tumors, others such as cell phone use and power frequency electromagnetic fields have not shown strong evidence of causation. The review emphasizes the need for further research to identify homogeneous subtypes of brain tumors and to develop more precise classifications based on genetic and molecular changes.This review provides an overview of epidemiological studies on primary brain tumors, aiming to encourage multidisciplinary research among surgeons, neuro-oncologists, epidemiologists, and molecular scientists. The review highlights the importance of understanding the causes of brain tumors, given their poor prognosis and the recent progress in molecular classification. It discusses the challenges in interpreting time trends in incidence and mortality, the role of geographic and ethnic variations, and the significance of survival and prognostic factors. The review also examines hereditary syndromes, polymorphisms in genes related to carcinogenesis, and noninherited endogenous, infectious, and environmental risk factors. While some factors like inherited mutations in TP53 and p53 have been linked to brain tumors, others such as cell phone use and power frequency electromagnetic fields have not shown strong evidence of causation. The review emphasizes the need for further research to identify homogeneous subtypes of brain tumors and to develop more precise classifications based on genetic and molecular changes.