Tong C, Huang C, Wu J, et al. - The prevalence of undiagnosed mild cognitive impairment (MCI) was determined in elderly patients undergoing thoracic surgery. Further, how it affects outcomes is investigated. Researchers conducted a prospective cohort study including 170 patients aged 65 years or older who were scheduled for thoracic surgery between November 7, 2018, and April 1, 2019, at the Shanghai Chest Hospital. The final analysis was performed on a total of 154 elderly patients who accomplished the Chinese version of the Montreal Cognitive Assessment test preoperatively. MCI was evident in 49.4% (76 of 154) of elderly patients undergoing thoracic surgery. This suggests a high incidence of MCI before thoracic surgery in elderly patients; it was noted to be correlated with a higher rate of adverse postoperative outcomes. These findings may have implications for preoperative patient counseling, operative planning, and eventually reducing potential risk exposure and related outcomes.