Objective To investigate the direct economic losses caused by hospital-acquired infections (HAI) in the hospitalized patients of an integrated intensive care unit (ICU). Methods A retrospective analysis was carried out on 32 patients with HAI from intensive medicine department of an upper first-class hospital during Jan. 2013 and Dec. 2014. They were assigned into the HAI group, and according to the ratio of 1∶1, another 32 matched patients served as the control group. The length of hospital stay, hospitalization expenses and the effect of infection sites on hospital stay were analyzed and compared between the 2 groups of patients. Results The length of hospital stay was 48.91 (14.25, 74.25) d and 13.47 (8.00, 12.75) d, respectively, in the infection group and control group, with significant difference between them (z=4.165, P<0.05). The total hospitalization expenses was 160 788.45(49 123.11, 223 523.13) RMB Yuan and 41 855.62 (24 684.55, 46 026.74) RMB Yuan, respectively. The expenses on Western medicine were the highest, followed by treatment fee, and the expenses were significantly higher in the infection group than in the control group (P<0.05). The length of hospital stay was significantly longer in the patients with multilocation infections than those with single site of infection ［(75.00±60.93) vs (16.64±9.91)d, t=2.82, P<0.05］. Conclusion Carrying out the economic loss assessment of HAI in ICU can more scientifically and effectively evaluate the economic losses caused by HAI, help the administers of medical institutions to increase financial support on the prevention and control of the infection, and save the limited medical resources, so as to reduce the economic burden of the patients.