Background and Aims: Inguinal hernia repair is one of the most common procedures performed in day surgery units. With the development of modern inguinal hernia surgery and anesthetic techniques, an increasing cases of inguinal hernia surgery can be done in day surgery units. However, there is no a uniform standard for the selection of procedure and anesthetic method in day surgery for inguinal hernia. Laparoscopic transabdominal preperitoneal hernia repair (TAPP), for the advantages such as minimal invasiveness, fast recovery, high patient comfort level and low recurrence rate, has become one of the main methods for clinical treatment of inguinal hernia. This study was conducted to evaluate the effectiveness and safety of day-case laparoscopic TAPP.  
Methods: The clinical data of the consecutive patients with inguinal hernia undergoing laparoscopic TAPP in Xiangya Hospital of Central South University from January 2016 to January 2021 were retrospectively analyzed, and a total of 785 patients were finally included in this study. All patients were evaluated by the surgeon and anesthesiologist before operation for decision-making on inpatient surgery or day surgery, of whom, 585 cases underwent inpatient surgery and 200 cases received day surgery. The 200 patients undergoing day-case laparoscopic TAPP were specially analyzed. 
Results: The average age of patients receiving day surgery was younger than that of patients undergoing inpatient surgery, and meanwhile, the proportions of cases with concomitant disease, recurrent hernia or bilateral hernia were less than those of patients undergoing inpatient surgery (all P<0.05). Laparoscopic TAPP was successfully performed in all patients of the two groups. The average length of total hospital stay was 0.5 d, the average postoperative length of stay was 6 h, and the average hospitalization expense (including outpatient examination cost) was 16 185 yuan for patients receiving day surgery, all of which were significantly lower than those for patients undergoing inpatient surgery (all P<0.05). Postoperative urinary retention occurred in one case in patients undergoing day surgery. The median follow-up period was 13 (2–62) months. One case (0.5%) in patients undergoing day surgery and 2 cases (0.3%) in patients undergoing inpatient surgery recurred, and the difference showed no statistical significance (P>0.05), and no long-term inguinal chronic pain, readmission and death were observed in patients of both groups during the follow-up period. 
Conclusion: Day-case laparoscopic TAPP can significantly reduce the length of hospital stay and hospitalization expenses compared with inpatient operation. It can be safely performed under the premise of reasonable selection of indications, for example, in most of young patients with less complications (American Society of Anesthesiologists grade II or below) and patients with simple inguinal hernia (such as incipient hernia, no incarceration or strangulation, and no relevant history of lower abdominal surgery).