BACKGROUND: The year 2009 was notable for the outbreak of a novel strain of influenzaA(H1N1).Wereport the outcomes of H1N1 infection in a large cohort of lung transplant (LTx) recipients and candidates. METHODS: This was a retrospective review of 22 suspected cases of H1N1 influenza screened using real-time polymerase chain reaction from nasal secretions. There were 15 confirmed cases (10 LTx recipients, 5 LTx candidates). RESULTS: All patients were treated with oseltamivir at the time of the first clinical assessment. In the LTx recipients group, 7 of the 10 confirmed cases were treated at home with oseltamivir alone. Three patients were admitted with complications (2 pneumonia, 1 acute rejection). Two patients required mechanical ventilation. Two patients had prolonged viral shedding. No deaths occurred among the LTx recipients. In the 5 LTx candidates with confirmed H1N1, 2 deaths occurred from pneumonia and acute respiratory distress syndrome. CONCLUSIONS: Influenza H1N1 had a significant complication rate amongst LTx recipients and a high mortality rate amongst LTx candidates. © 2010 International Society for Heart and Lung Transplantation. All rights reserved.