Rapid diagnosis and choice of appropriate antibiotic treatment might be life-saving in serious infectious diseases. Still the available markers that can evaluate and monitor the diagnosis and treatment are few. Hepatocyte growth factor (HGF) has been studied as a potent regenerative factor produced and released during injuries such as infectious diseases. Monitoring of HGF levels might predict therapy results better than C-reactive protein (CRP) within the first day of treatment in pneumonia. For further investigation of previous observations we aimed to study HGF as a first-day marker in over-representing infectious diseases in comparison to procalcitonin (PCT), CRP and body temperature. Fifty-one patients with community acquired infectious diseases were included consequently at admittance and the serum samples were collected before and within 18 - 24 hours of treatment. HGF levels decreased significantly in case of efficient antibiotic therapy and HGF was shown to be better than PCT, CRP and body temperature to evaluate treatment. In patients with pneumonia, monitoring of HGF was most reasonable. HGF might be used as a therapeutic marker within the first day of empiric antibiotic treatment during infection.