An increasing number of patients receive extracorporeal membrane oxygenation (ECMO) for life support. This study aimed to investigate the incidence and risk factors for nosocomial infection in adult patients receiving ECMO. We reviewed the medical records of adult patients who received ECMO support for more than 72h at Far Eastern Memorial Hospital from 2001 to 2007. ECMO-related nosocomial infections were defined as infections occurring from 24h after ECMO initiation until 48h after ECMO discontinuation. There were 12 episodes of nosocomial infection identified in 10 of the 114 (8.77%) patients on ECMO, including four cases of pneumonia, three cases of bacteraemia, three surgical site infections and two urinary tract infections. The incidence of ECMO-related nosocomial infection was 11.92 per 1000 ECMO-days. The length of ECMO use and intensive care unit (ICU) stay were significantly different between patients with, and without, nosocomial infection (P<0.001). More than 10 days of ECMO use was associated with a significantly higher nosocomial infection rate (P=0.003). Gram-negative bacilli were responsible for 78% of the nosocomial infections. In the univariate analysis, the duration of ICU stay and duration of ECMO use were associated with nosocomial infection. In the multivariate analysis, only the duration of ECMO was independently associated with nosocomial infection (P=0.007). Overall, the only independent risk factor for ECMO-related nosocomial infection identified in this study was prolonged ECMO use.