Purpose This study aimed to evaluate factors contributing to unplanned admissions in patients scheduled for day-only laparoscopic cholecystectomy (DOLC) in a high-volume ASC. Methodology Retrospective analysis of 664 DOLC patients (2021–2024). Key quality measures included perioperative hypothermia, analgesia efficacy, PACU monitoring, Clavien-Dindo complications and adherence to ERAS protocols. Hypothermia, readmission, and transfer rates were assessed against U.S. ASC quality benchmarks. Results 116/664 patients (17.5%) had failed DOLC. Factors associated with admission included age >60 yrs (p=0.007), higher intraoperative opioid doses (p=0.047) and higher total PACU opioid doses (p<0.0001). Univariate analysis found younger age (mean 45.7 vs. 49.4 yrs,p=0.024), lower BMI (30.17 vs. 31.90,p=0.014), TAP block (p<0.0001), shorter surgical times (64.78 vs. 75.33 mins,p<0.0001) increased successful DOLC. MVA confirmed age, BMI and surgical duration as significant independent predictors of failed DOLC. Common reasons for unplanned admission included postoperative pain (14.6%), intraoperative complications (12.9%), medical conditions (10%), late finishes (8.6%), nausea or vomiting (6%), intraoperative medical complications (5%), or abnormal IOC (4.3%). Abdominal drains were placed in 31.9% of cases. Additional factors included transport issues (0.86%) or lack of family support. Conclusions The nature of unplanned overnight admissions underscores the need for improvement in perioperative management. Standardized protocols focusing on patient selection, ERAS protocol adherence, and optimizing surgical and anaesthetic practices may reduce overnight stays, readmissions and transfers, enhancing patient care and performance of DOLC.