This record contains raw data related to article “single-cell transcriptomic reveals functional heterogeneity of myeloid cells in glioma microenvironment." High grade gliomas (HGG) are highly aggressive tumors with a particularly severe prognosis and an unmet medical need. HGG are characterized by a high degree of heterogeneity due to genetic and metabolic driving forces, either within and between individual patients. Temporal and spatial HGG heterogeneity contributes to response variability to conventional and adjuvant therapies among patients. HGG are also highly infiltrated by immune cells, tumor-associated macrophages (TAM) in particular, which are key drivers of the local immunosuppression supporting HGG progression and its resistance to immunomodulating therapeutic strategies. As the impact of HGG heterogeneity on macrophage biology remain poorly understood, we perform single-cell RNA sequencing, that reveals a large and dynamic myeloid landscape in patients with primary or secondary gliomas. To define the role in local immunosuppression and tumor progression, resident microglia and monocyte-derived macrophages are characterized, exhibiting additional heterogeneity across glioma subtypes. Understanding the immunosuppressive mechanisms operating in HGG is key to guide patients’ selection and optimize success rate of immunomodulating therapies.