The measurement of non-specific inflammation parameters, such as erythrocyte sedimentation rate (ESR), fibrinogen, C-reactive protein (CRP) and procalctinon (PCT) are very important tools for diagnosis of infections, as well as for monitoring of treatment response. The aim of this study was to determine the significance of non-specific inflammatory parameters in patients with influenza H1N1 infection. ESR, fibrinogen, CRP and PCT were analyzed in patients with influenza H1N1 infection. The diagnosis of influenza H1N1 was established from the nasopharyngeal swabs using Real Time Polymerase Chain Reaction – (RT PCR) method. Chest X-ray was performed to diagnose pneumonia Sixty-three out of 340 hospitalized patients with influenza had pandemic influenza. Their mean age was 34.60±13.82years. They were referred to hospital 1 to 7 (4.06±2.0) days after onset of symptoms. Of these, 46 had pneumonia, while the majority (41 patients) had interstitial pneumonia, and only five had lobar or segmental pneumonia. Patients with pneumonia had significantly higher levels of CRP and PCT in comparison with those without pneumonia. Patients with lobar pneumonia had significantly higher CRP than those with interstitial pneumonia. However, mean values of PCT between interstitial and lobar pneumonia cases did not differ significantly. Interstitial pneumonia was the most common complication of H1N1 infection among our patients. Non-specific parameters of inflammation, especially CRP and PCT were increased in all pneumonia cases, regardless of the etiology. Monitoring of non-specific inflammatory parameters in patients with H1N1 infection allows recognition of patients with complications, their prompt hospitalization and early initiation of antimicrobial therapy.