Hospital-acquired infections add considerable morbidity and mortality to patient care. However, a detailed economic analysis of these infections on an individual case basis has been lacking. The authors examined both the hospital revenues and expenses in 54 cases of patients with central line-associated bloodstream infections (CLABs) over 3 years in 2 intensive care units and compared these financial data with patients who were matched for age, severity of illness on admission, and principal diagnosis. The average payment for a case complicated by CLAB was $64 894, and the average expense was $91733 with gross margin of -$26 839 per case and a total loss from operations of $1 449 306 in the 54 cases. The costs of CLABs and the associated complications averaged 43% of the total cost of care. The elimination of these preventable infections constitutes not only an opportunity to improve patient outcomes but also a significant financial opportunity.