Recently, the World Health Organization (WHO) classification of tumours of the central nervous system (CNS) has brought essential changes. The currently valid revised WHO 2016 classification of CNS tumours introduced the concept of integrated diagnostics, which incorporated not only histopathological morphological finding and immunophenotype but also molecular-genetic characteristics of the tumour. Thus, the final integrated diagnosis comprises the traditional morphological and growth pattern characteristics of a tumour including histopathological grade and also specific molecular biomarkers. The classification of tumour based on a combination of both tumour phenotype and genotype enables more precise prognostic stratification, increases the objectivity of diagnostics and prediction of response to treatment. In 2017, an international platform, The Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy – not official WHO (cIMPACT-NOW), was established to create and formulate practical recommendations for integrated diagnostics of CNS tumours and upcoming WHO classification. The incorporation of molecular biomarkers into the integrated diagnostics radically changed the classification of diffuse gliomas, which include entities with different morphological characteristics, genetic alterations and biological behaviour. This review article summarizes essential mor-phological, immunophenotypical and molecular genetic characteristics of diffuse gliomas within the scope of integrated diagnostics according to the valid WHO classification of tumours of the CNS and subsequent recommendations of diagnostic approaches.