Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Despite intensive research efforts and a multimodal management that actually consists of surgery, radiotherapy and chemotherapy with temozolomide, the prognosis is dismal. The aim of the current observational study is to determine immune phenotypes in individual patients with GBM at the time of diagnosis and to correlate tumor size, location (imaging), tumor properties (isocitrate dehydrogenase - 1 (IDH-1), o6-methylguanine-DNA-methyltransferase (MGMT), epidermal growth factor receptor (EGFR) mutation status, etc.) with clinical data, such as progression free and overall survival, Karnofsky index (progression free survival (PFS),overall survival (OS), Karnofsky score( KFS)), with blood immune phenotypes, biomarkers, and immune histochemical results of tumor infiltrating lymphocytes, macrophages, myeloid derived suppressor cells (MDSC), etc.. The different immunological phenotypes could predict a positive response to specific immunological therapeutic strategies and select the individual therapeutic plan for an individual GBM patient.