© 2014 Elsevier B.V. Background: Increased inflammation, endothelial dysfunction, and structural brain abnormalities have been reported in both schizophrenia and bipolar disorder, but the relationships between these factors are unknown. We aimed to identify associations between markers of inflammatory and endothelial activation and structural brain variation in psychotic disorders. Methods: We measured von Willebrand factor (vWf) as a marker of endothelial cell activation and six inflammatory markers (tumor necrosis factor-receptor 1, osteoprotegerin, interleukin-1-receptor antagonist, interleukin-6, C-reactive protein, CD40 ligand) in plasma and 16 brain structures obtained from MRI scans of 356 individuals (schizophrenia spectrum; n = 121, affective spectrum; n = 95, healthy control subjects; n = 140). The relationship between the inflammatory and endothelial markers and brain measurements were investigated across groups. Results: There was a positive association (p=2.5×10-4) between plasma levels of vWf and total volume of the basal ganglia which remained significant after correction for multiple testing. Treatment with first generation antipsychotics was associated with basal ganglia volume only (p=0.009). After adjusting for diagnosis and antipsychotic medication, vWf remained significantly associated with increased basal ganglia volume (p=0.008), in particular the right globus pallidus (p=3.7×10-4). The relationship between vWf and basal ganglia volume was linear in all groups, but the intercept was significantly higher in the schizophrenia group (df=2, F=8.2, p=3.4×10-4). Conclusion: Our results show a strong positive correlation between vWf levels and basal ganglia volume, in particular globus pallidus, independent of diagnosis. vWf levels were significantly higher in schizophrenia, which could indicate a link between endothelial cell activation and basal ganglia morphology in schizophrenia patients.