A 30-year-old married woman with a history of infertility was referred to the general surgery department with complaints of occasional and intermittent left lower abdominal and left inguinal pain. Abdominal examination was normal and there was no obvious bulging in the left inguinal region. Routine laboratory tests were normal. Abdominal and pelvic ultrasonography revealed a left inguinal hernia with a defect of 15 millimeters (mm) and did not report any other pathological points. The patient was a candidate for laparoscopic transabdominal preperitoneal (TAPP) inguinal hernia repair. During the operation, pneumoperitoneum was performed through the umbilical region using a Veress needle, and after inserting a 10 mm umbilical port and exploring the abdomen, blood was seen in the pelvis. It was determined that the bleeding was from the mesentery of the small intestine (a known iatrogenic complication caused by Trocar or Veress needle). Two more 5 mm ports were inserted, the mesenteric bleeding was ligated using a ligature, and it was decided to continue the surgery laparoscopically. No obvious hernia was seen in the exploration of the inguinal area. After intra-abdominal blood suction, it was determined that there was a retroperitoneal hematoma in zone one. The patient's vital signs were still stable. After some patience, it became clear that the hematoma was expanding, so a decision was made to perform a laparotomy. Zone one was explored, and it was found that there was a perforation in front of the inferior vena cava, and there was heavy bleeding, so after controlling the proximal and distal vein, the perforation site was repaired using Prolen threads. In pelvic exploration, there was extensive adhesion in the region of the ovaries, fallopian tubes, and uterus, but there was no mass in the ovaries. Full abdominal exploration was performed. There was a mass in the small intestine 15 centimeters (cm) from the ileocecal valve, which caused an almost complete obstruction. Considering the patient's stable vital signs, a decision was made to resect the mass, and anastomose of the small intestine. At the end of the surgery and after washing the abdomen, the opened peritoneum was repaired on the vein, and two drains were placed in the pelvis. On the third day of surgery and after bowel habits returned, a liquid diet was started. On the fifth day, the patient had a good general condition, so the drains were removed and she was discharged. The histopathology examination of the small intestine mass showed endometriosis. The patient was referred to a gynecologist for consultation and treatment.