Hepatocyte growth factor (HGF) is a multifunctional growth factor. After lung injury HGF is secreted in the lung and promotes reconstruction of the damaged organ. We measured, retrospectively, the serum HGF concentrations collected on admission in 55 patients with bacterial pneumonia, using an enzyme-linked immunosorbent assay (ELISA). The patients were divided into 3 groups: Group 1 was survivors with normal liver function (n = 14), Group 2 was survivors with abnormal liver function (n = 31) and Group 3 was non-survivors (n = 10). Median concentrations of HGF were elevated in Groups 1 and 2; and no statistically significant difference between these 2 groups was found. Group 3 had a median HGF concentration within the reference range, significantly lower than both Group 1 and Group 2. In addition LDH was significantly higher in non-survivors as compared with survivors. The combination of LDH and HGF concentrations discriminated between survivors and non-survivors (sensitivity 0.90 and specificity 0.96). The results support the hypothesis that increased levels of HGF might be a natural part of the healing process of lung injury, irrespective of liver involvement, and that patients without increased HGF levels, especially those with concomitant liver function impairment, may have a poor prognosis.