BACKGROUND: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the leading causes of death after lungresection. Neutrophil elastase is thought to be an important mediator in the pathogenesis of ALI. Sivelestat is a new neutrophil elastase inhibitor which may improve the outcome in patients with ALI/ARDS after lung resection. The objective of this study was to determine whether or not sivelestat can reduce mortality in patients with ALI after pulmonary resection for lung cancer. METHODS: This study was a retrospective case-control study of twenty three patients who developed ALI/ARDS within seven days of lung resection for lung cancer. The control group (n = 12) received standard care, while the sivelestat group (n = 11) received a continuous infusion of sivelestat (0.2 mg/kg/hr) for seven days in addition to standard care. RESULTS: There was no significant difference in the baseline characteristics between the control and sivelestat groups, except for heart rate. Six of twelve patients (50%) in the control group survived, while seven of twelve patients (64%) survived in the sivelestat group (p = 0.34). There was also no significant difference between the two groups in the progression to ARDS. In the sivelelestat group, survivors had lower APACHE II and SOFA scores than the patients in the control group. CONCLUSIONS: There was no additional effect of a neutrophil elastase inhibitor in the treatment of ALI after pulmonary resection for lung cancer.