Background: Systemic immune-inflammation states across the heterogeneous population of brain metastases are very important in the context of brain-immune bidirectional communication, especially among the patients needing neurosurgical resection. Four blood cell ratios based on complete blood count (CBC) test serving as prognostic biomarkers have been highlighted by previous studies, including systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR). However, the presurgical systemic immune-inflammation landscape in brain metastasis needing neurosurgical resection is limited. Methods: Patients with brain metastases admitted to the Department of Neurosurgery at the National Cancer Center, Cancer Hospital of Chinese Academy of Medical Sciences between January 2016 and December 2019 were included. Based on peripheral blood cell counts in CBC test before neurosurgical resection, four systemic immune-inflammation biomarkers (SII, NLR, PLR, and LMR) were calculated. We characterized the changes of SII, NLR, PLR, and LMR in patients with brain metastasis before neurosurgical resection and the associations of these types of immune-inflammation states with patient demographics. In parallel, the corresponding data from the relative healthy populations without systemic diseases were enrolled as the control in the present study. Results: Brain metastases induced systemic immune-inflammation perturbation, which was characterized by a significant increase in SII (p < .01) and NLR levels (p < .01) and a significant decrease in the LMR level (p < .01) in comparison with the healthy control group. Moreover, patients with male gender, less Karnofsky Performance Status (KPS) scores (<70), specific pathological subtypes, extracranial transfer, and history of both systemic and radiation therapy may have significant differences in one or more of these biomarkers, which indicated poorer systemic immune-inflammation states. Conclusions: This study provides evidence that brain metastasis is associated with perturbations in presurgical systemic immune-inflammation states. We should pay attention to the systemic immune-inflammation perturbations following brain metastasis in clinic, especially in the subpopulations with high risks.