OBJECTIVE: To study the changes of serum concentrations of caspsase-1 and IL-18 in newborns with hypoxic-ischemic encephalopathy (HIE) and to study the correlation between caspsase-1 and IL-18 and the severity of HIE. METHODS: Serum concentrations of caspsase-1 and IL-18 were measured by enzyme-linked immunosorbent assay (ELISA) in 70 newborns with HIE and 22 normal control subjects. RESULTS: Serum concentrations of caspsase-1 and IL-18 in infants with HIE were significantly higher than those in control subjects(P<0.05). Both serum caspsase-1 and IL-18 concentrations were associated with the severity of HIE. Severe HIE neonates had the highest serum caspsase-1 and IL-8 levels, followed by moderate HIE neonates. There was a significantly positive correlation between serum caspase-1 and IL-18 levels (γ=0.6677, P= 0.0013). CONCLUSIONS: Caspsase-1 and IL-18 may be useful markers for the early diagnosis of HIE and also for the evaluation of the severity of HIE.