OBJECTIVE: Previous studies have shown that elevated depressive symptoms are associated with increased risk of postoperative delirium. However, to our knowledge no previous studies have examined whether different components of depression are differentially predictive of postoperative delirium. METHODS: One thousand twenty patients were screened for postoperative delirium using the Confusion Assessment Method and through retrospective chart review. Patients underwent cognitive, psychosocial, and medical assessments preoperatively. Depression was assessed using the Geriatric Depression Scale-Short Form. RESULTS: Thirty-eight patients developed delirium (3.7%). Using a factor structure previously validated among geriatric medical patients, the authors examined three components of depression as predictors of postoperative delirium: negative affect, cognitive distress, and behavioral inactivity. In multivariate analyses controlling for age, education, comorbidities, and cognitive function, the authors found that greater behavioral inactivity was associated with increased risk of delirium (OR: 1.95 [1.11, 3.42]), whereas negative affect (OR: 0.65 [0.31, 1.36]) and cognitive distress (OR: 0.95 [0.63, 1.43]) were not. CONCLUSION: Different components of depression are differentially predictive of postoperative delirium among adults undergoing noncardiac surgery.