The objective of this study was to identify differences between nursing home (NH) and nonnursing home (non-NH) patients with bacteremia regarding host risk factors, exposures, microbiology, and outcome. Between October 1995 and February 1998, 134 episodes of true bacteremia were identified at the North Chicago Veterans Administration Medical Center (NCVAMC). Seventy-eight episodes of bacteremia occurred in NH patients who stayed for at least 3 months in the NH at the NCVAMC and developed bacteremia there or 48 hours after admission to the acute care hospital (ACH). Fifty-six episodes occurred in the non-NH patients who developed bacteremia in the community or 48 hours after admission to the ACH. NH patients were more likely to be older than 65 years (88% vs. 71%, P = 0.0334) and to have pressure sores (25% vs. 5%, P = 0.005), urinary incontinence (42% vs. 27%, P = 0.0471), and mental illness (62% vs. 29%, P = 0.0001) than non-NH patients. Coagulase-negative Staphylococcus and Escherichia coli were the most common causes of bacteremia occurring as frequently in both groups. Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and enterococcal bacteremia were comparable, whereas vancomycin-resistant enterococci, ceftazidime-resistant E. coli, Klebsiella pneumoniae, and Enterobacter were rarely isolated. Twelve (15%) NH patients died within 2 weeks of acquiring bacteremia compared with 4 (7%) non-NH patients (P = 0.1176). For ACH-acquired cases, 20 NH patients were similar to 26 non-NH patients with regard to hospital stay; exposure to antibiotics, steroids, intensive care setting, surgery, tube feeding, and urinary and vascular catheters prior to bacteremia. Although NH and non-NH patients with bacteremia have different host characteristics, they have similar in-hospital exposures, distribution of infecting organisms, and outcome.