Patient perception of physician compassion may be associated with improved health outcomes, yet it is unclear whether it is associated with postoperative pain reduction or improved patient experience metrics in same-day surgery patients. We hypothesized that higher anesthesiologist compassion during the preanesthesia interview, rated by patients, is associated with lower postoperative pain via the anxiety pathway in same-day surgery patients. We also performed exploratory correlation analysis to assess whether compassion was associated with less opioid consumption and improved patient experience in same-day surgery patients. We conducted a single-center, prospective, observational cohort study in American Society of Anesthesiologists (ASA) physical status I to III patients scheduled to undergo same-day surgery with anesthesia. Compassion was scored using a validated 5-item tool. State anxiety (SA) and trait anxiety (TA) were measured using the State-Trait Anxiety Inventory. Pain scores were obtained using a 0 to 10 Likert scale. Daily opioid use was recorded. Patient experience was assessed using the Consumer Assessment of Healthcare Providers and Systems Outpatient and Ambulatory Surgery Survey (OAS CAHPS) and the Surgical Care CAHPS. Mediation analysis was used to assess the association between compassion and pain scores via the anxiety pathway. Spearman correlation was performed to test for association between the compassion score and the secondary outcomes. A total of 147 subjects completed the study with a median age of 50 years and 81% female. Fifty percent underwent breast surgery, 35% abdominal surgery, and the rest underwent gynecological and urological surgeries. The median (Q1-Q3) postoperative pain scores on postoperative days 0 and 3 days later were 4 (1.5-6) and 3 (1-5), respectively.Mediation analysis results showed a same-day anxiety-mediated effect (95% confidence interval [CI]) of compassion on pain of -0.08 (-0.13 to -0.02), attributing to 9% of the total effect. On postoperative day 0, an increase in compassion was associated with a significant average drop in pain of between 0.02 and 0.13. In addition, higher compassion was correlated with better patient experience metrics (ρ= -0.53 [95% CI, -0.64 to -0.39]). The study results suggest that an anxiety-mediated pathway exists through which compassionate care may help improve the patient's perception of postoperative pain on the day of surgery (before discharge from the hospital). Higher compassion was also associated with better patient experience metrics.