Inflammation, angiogenesis, and coagulation are linked to the development of cancer. In glioblastoma, microvascular proliferation is a hallmark, and lymphocytic infiltration is a common finding. Thromboses are frequent in patients with glioblastoma. The objective of this study was to assess presurgical levels of circulating markers of inflammation, angiogenesis, and coagulation in a prospective series of patients with glioblastoma, and to explore their correlations and possible associations with clinical findings. Angiogenesis markers included were vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor-receptor 1 (sVEGFR-1), and thrombospondin-1 (TSP-1). Inflammatory markers included were C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and sialic acid (SA). Coagulation markers included were fibrinogen (Fg), endogen thrombin generation (ETG), prothrombin fragments 1 + 2 (F1 + 2), and tissue factor (TF). Forty-seven patients and 60 healthy subjects were included in the study. Signs of tumor necrosis in presurgical MRI were associated with shorter survival (P < 0.01). All inflammation markers, F1 + 2, ETG, VEGF and sVEGFR-1, were significantly elevated in glioblastoma patients. Correlations were found between ETG and Fg (r = 0.44, P < 0.01). Sialic acid correlated with Fg (r = 0.63, P < 0,001); CPR correlated with SA (r = 0.60, P < 0.001), Fg (r = 0.76, P < 0.001), TNFα (r = 0.56, P < 0.001), and IL-6 (r = 0.65, P < 0.001); and IL-6 also correlated positively with TNFα (r = 0.40, P < 0.02) and Fg (r = 0.45, P < 0.01). Vascular endothelial growth factor inversely correlated with sVEGFR-1 (r = -0.35, P < 0.02). No associations were found between marker levels and survival or progression-free survival.