Objective To investigate the effects of treatment of hernia sac stump in laparoscopic transabdominal preperitoneal inguinal hernia repair (TAPP) on postoperative seroma. Methods The prospective study was conducted. The clinical data of 128 male patients with primary indirect inguinal hernia who were admitted to Fujian Medical University Union Hospital from October 2017 to March 2019 were selected. Patients were divided into two groups by random number method. Patients in experimental group had hernia sac stump sutured and fixed at the lower margin of rectus abdominis after transection of hernia sac in TAPP, and patients in control group had hernia sac stump free in the abdominal cavity after dissection and transection of hernia sac in TAPP. Observation indicators: (1) surgical situations; (2) follow-up. Follow-up using outpatient examination and telephone interview was conducted to detect the incidence of postoperative seroma, incision infection, chronic pain, and hernia recurrence up to June 2019. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was done using the t test. Measurement data with skewed distribution were represented as M (range), and comparison between groups was done using the Mann-Whitney U test. Count data were described as absolute numbers and percentages, and comparison between groups was analyzed using the chi-square test. Results A total of 128 male patients were screened for eligibility, including 60 patients in the experimental group and 68 patients in the control group. The 128 patients were aged from 47 to 74 years, with an average age of 61 years. (1) Surgical situations: operation time and hospital expenses were (102±34)minutes and (12 813±2 390)yuan for the experimental group, and (97±30)minutes and (12 125±2 205)yuan for the control group, respectively, showing no significant difference between the two groups (t=0.907, 1.685, P>0.05). (2) Follow-up: all the 128 patients received follow-up. There were 8 cases of seroma in both the experimental group and the control group, with no significant difference between the two groups (χ2=0.072, P>0.05). The extraction volume of patients with seroma was 20 mL (range, 4-31 mL) in the experimental group, and 43 mL (range, 23-98 mL) in the control group, showing a significant difference between the two groups (Z=-2.013, P<0.05). There was no incision infection, chronic pain or hernia recurrence in 3 months after operation in patients with seroma of either experimental group or control group. Conclusions During TAPP, suture and fixation of the hernia sac stump to the lower edge of rectus abdominis and free hernia sac stump in the abdominal cavity after dissection and transection of hernia sac can effectively repair indirect inguinal hernia. The former method can reduce the extraction volume of seroma after operation. Key words: Hernia; Indirect inguinal hernia; Transabdominal preperitoneal inguinal hernia repair; Seroma; Laparoscopy; Prospective study