Infection with antibiotic-resistant Acinetobacter spp. is an increasing problem in critical care environments worldwide. Acinetobacter spp. are known to produce an insulin-cleaving protease. We hypothesized that infection with Acinetobacter spp. was associated with the acquisition of glucose intolerance in burn patients. Data were collected prospectively on all 473 patients admitted to the Burns Centre between January 2002 and March 2003. A total of 3.4% of patients acquired glucose intolerance during admission. Patients with Acinetobacter spp. infection were 9.8 times more likely to develop glucose intolerance than those without the infection (P < .0001). The association persisted after controlling for TBSA (P < .001). In patients with deep Acinetobacter spp. infection, 47% had glucose intolerance, compared with 12% in those with infection of the burn only (P = .03). In patients with pre-existing diabetes mellitus, 27% developed Acinetobacter spp. infection compared with only 8.5% of patients without diabetes (P = .04). This study demonstrates a clear association between Acinetobacter spp. infection and glucose intolerance in burns patients.