Objective To analyze the characteristics and risk factors of healthcare-associated infection (HAI) in patients receiving veno-venous extracorporeal membrane oxygenation (V-V ECMO) treatment. Methods Clinical data of 141 patients who received V-V ECMO treatment in the intensive care unit (ICU) of a tertiary first-class hospital in Qingdao from January 2019 to November 2023 were collected. Patients were divided into the infection group and non-infection group based on whether HAI occurred. Characteristics of HAI were analyzed, risk factors were analyzed by univariate and multivariate logistic regression analyses. Results Among 141 V-V ECMO patients, incidence of HAI was 37.59% (n=53). A total of 81 strains of pathogens were isolated from patients in the infection group, Gram-negative bacteria accounted for 56.79% (n=46), mainly Acinetobacter baumannii, which was up to 28.39% (carbapenem-resistant Acinetobacter baumannii ［CRAB］ accounted for 16.05%). The main type of HAI in V-V ECMO patients was pulmonary infection alone (54.72%), followed by bloodstream infection alone (20.75%), multi-site infection accounted for 22.64%. Univariate analysis result showed that compared with the non-infection group, there were statistically significant differences in the history of immunosuppressive agents use, ICU transfer history, surgical history, fiberbronchoscopy, renal replacement therapy, duration of ICU stay, duration of tracheal intubation and/or tracheotomy, duration of urinary catheterization, duration of gastric tube placement, duration of central venous catheterization, duration of antimicrobial use, and duration of V-V ECMO support (all P<0.05). Multivariate logistic regression analysis result showed that ICU transfer history and fiberbronchoscopy were independent risk factors for HAI in V-V ECMO patients (OR=6.850, 4.643, respectively, both P<0.05). Conclusion Hospitals should take effective prevention and control measures based on the characteristics and related risk factors of HAI in patients receiving V-V ECMO treatment to reduce the occurrence of HAI.