ObjectivePatients with intracerebral hemorrhage (ICH) may elaborate varying degrees of perihematomal edema (PHE), requiring closer monitoring and a higher intensity of treatment. Here, we explore whether the soluble form of CD163, a scavenger receptor responsible for hemoglobin sequestration, can serve as a prognostic biomarker of PHE development and poor outcome after ICH.MethodsOur study cohort was comprised of 51 primary age‐ and sex‐matched ICH patients with moderate‐sized, hypertensive deep hemorrhages. Patients were part of a prospective ICH registry cataloguing admission data along with functional outcomes. We measured sCD163 levels in serial serum and cerebrospinal fluid (CSF) samples obtained at prespecified timepoints. Descriptive statistics, including a generalized estimating equation for longitudinal data, were used to analyze sCD163 in relation to ICH outcomes.ResultsAcute serum sCD163 (<48 h postictus) was significantly elevated in ICH patients compared to both acute neurological event controls (P = <0.001) and healthy controls (P = 0.003). As predicted, acute serum sCD163 levels were significantly associated with both hematoma volume expansion (P = 0.009) and PHE expansion (P = 0.002). Further examination determined that patients with high PHE expansion had poorer modified Rankin Scale scores at discharge (P = 0.024), and circulating sCD163 levels were found to be significantly lower in patients with high‐level PHE expansion.InterpretationAcute sCD163 levels may be a useful biomarker for the acute identification of patients at risk for hematoma expansion, perihematomal edema expansion and poorer short‐term outcomes.