This study aimed to investigate the immunological profile of Chronic Subdural Hematoma (CSDH) subtypes based on their radiological appearances, with a focus on comparing the membranous CSDH to other subtypes. We prospectively analyzed 170 CSDH cases from 138 patients, categorizing them into 'Membranous' and 'Other' subtypes based on computed tomography scans. Samples were collected from the subdural fluid and systemic blood and analyzed for a panel of inflammatory markers. Demographic data, clinical characteristics, and time since trauma were also assessed. Time since trauma to diagnostic CT was significantly longer for the 'membranous' subtype (p=0.001). 'Membranous' CSDH exhibited a distinct immunoprofile, including lower hemoglobin levels (p=0.0002) and higher concentrations of MMP-9 (p=0.005) and IL-8 (p<0.0001). Additionally, 'Membranous' CSDH showed elevated levels of IP-10, MIG, and uPAR compared to 'Other' subtypes, with significant correlations between IP-10 and MCP-1 (p=0.013), MIG (p=0.002), and uPAR (p=0.006). IL-8 levels also correlated significantly with MCP-1 (p=0.02), suggesting distinct inflammatory pathways in the 'Membranous' subtype CONCLUSIONS: This study demonstrates that CSDH subtypes, particularly the 'Membranous' subtype, possess a distinct immunological profile. These findings provide novel insights into CSDH pathophysiology. The unique inflammatory landscape of 'Membranous' CSDH, marked by elevated MMP-9 and IL-8 levels, may contribute to its chronic nature.