Objective To investigate characteristics and risk factors of healthcare-associated infection (HAI) in patients receiving extracorporeal membrane oxygenation (ECMO) support therapy. Methods Clinical data of patients receiving ECMO support therapy from January 2013 to December 2019 were collected retrospectively, characteristics and risk factors of HAI after ECMO were analyzed statistically. Results Among 163 patients receiving ECMO support therapy, 39 (23.93%) developed HAI after ECMO, lower respiratory tract infection (n=38, 59.38%) was predominant, followed by bloodstream infection (n=9, 14.06%) and digestive system infection (n=6, 9.37%). A total of 95 strains of pathogens were isolated, including 74 strains (77.89%) of Gram-negative bacilli, 20 strains (21.06%) of fungi, and 1 strain (1.05%) of Gram-positive coccus; pathogens were mainly isolated from sputum specimens (n=73 strains, 76.84%), followed by blood specimens (n=11 strains, 11.58%) and urine specimens (n=4 strains, 4.21%). There were significant differences in hospitalization days, antimicrobial use days, ventilator use days, urinary catheterization days and central venous catheterization days between patients with and without HAI after ECMO support therapy (all P < 0.001). Conclusion Patients receiving ECMO had high incidence of HAI, health care workers should take effective preventive measures against risk factors, so as to reduce the incidence of HAI.