Objective To study the direct economic loss due to healthcare-associated infection (HAI) in hospita-lized patients, enhance health care workers' awareness on prevention and control of HAI, and improve the ability of prevention and control of HAI. Methods A retrospective survey was conducted on hospitalized patients with respira-tory tract HAI, bloodstream HAI, gastrointestinal tract HAI, surgical site infection and urinary tract HAI in a tertiary hospital of Inner Mongolia Autonomous Region from January 1 to December 31, 2017, case group (HAI) and control group (non-HAI) were 1:1 mached according to maching standard, Wilcoxon test was used to analyze the direct economic loss caused by HAI. Results 262 pairs of patients were matched successfully, direct economic loss due to HAI of each patient was 31 300 Yuan, and the highest direct economic loss was 100 857 Yuan in intensive care unit. Difference in total hospitalization expense, length of hospital stay between two groups of patients were both statistically significant (both P<0.05); differences in bed fee, nursing fee, western medicine fee, operation fee, treatment fee, laboratory test fee and examination fee between two groups of patients were all statistically significant (all P<0.05), the highest expense was western medicine (14 378 Yuan). Difference in average overall expense and length of hospital stay between two groups of patients of patients were both statistically significant (both P<0.05). The average overall expense of hospitalization in different HAI sites from high to low were as follows:surgical site (47 469 Yuan), bloodstream (42 498 Yuan), urinary tract (34 598 Yuan), gastrointestinal tract (33 296 Yuan), and respiratory tract (31 058 Yuan). The average length of hospital stay of patients in case group extended by 7 days,difference in average length of hospital stay between two groups of patients was statistically significant (P<0.05). Conclusion HAI can lead to the increase of medical expense and prolongation of average length of hospital stay, and bring about greater loss to patients.