The purpose of this study was to describe the demographic and clinical features of hospitalized patients with the pandemic H1N1 influenza A virus infection in a tertiary care hospital in Central Anatolia, Turkey. The patients, all over 16 years of age and hospitalized for influenza-like symptoms between 1 November 2009 and 31 December 2009, were retrospectively identified from the records of the Infectious Diseases Department. Eighty patients whose diagnoses were confirmed by real-time PCR were included in this study. The median age of the patients was 27 years; 41 of them were male. Thirty-seven of the patients had a radiologically proven pneumonia. Eighteen of 37 (48.6%) patients with pneumonia had an underlying co-morbid medical condition, and 14 required intensive care unit admission. Patients with pneumonia had higher levels of C-reactive protein. All patients but one received oseltamivir treatment. Six patients with pneumonia received only antiviral therapy, while 31 of the patients with pneumonia received concomitant antibiotic therapy. Three patients who required mechanical ventilatory support died due to respiratory insufficinency. Although our study implicates the later periods of the pandemic, there were no significant differences for patients' characteristics between our study and previous reports from the countries where the pandemic first occurred.