TRALI incidence by year at 2 academic medical centers (2006-2009). Reduction of high-risk plasma was implemented from 2007 to 2008. In 2006, neither center had started TRALI mitigation. In 2009, both centers had completed TRALI mitigation. The annual TRALI incidence decreased from 2.57 (95% CI, 1.72-3.86) per 10 000 units transfused (23 cases/89 321 units) in 2006 to 0.81 (95% CI, 0.44-1.49) per 10 000 units transfused (10 cases/123 731 units) in 2009. *P = .002. There was an estimated 35% reduction in TRALI per year by trend analysis (95% CI, 21%-47%, P < .0001).