OBJECTIVE: Laparoscopic surgery offers many advantages compared to invasive surgery but one of the main problems is postoperative pain, partially resulting from the peritoneal inflammatory process mediated by inflammatory cytokines. The rationale of this study is that intraperitoneal washing could remove inflammatory mediators that are the cause of postoperative pain and could help in the removal of CO2 from the abdominal cavity. This article aims to analyze the effects of peritoneal lavage in the reduction of postoperative shoulder pain. PATIENTS AND METHODS: 277 patients enrolled to undergo laparoscopic gynecologic surgery were included in the study. Women are randomized into two groups, according to the use or non-use of peritoneal lavage with saline solution at the end of laparoscopic gynecological major procedures. RESULTS: Data show that the peritoneal lavage can significantly reduce postoperative pain in the first 36 hours after surgery, as well as patients' requests for analgesics: during the first 3 postoperative days, requests for paracetamol were lower in the YW (Yes Washing) group than the NW (No Washing) group (77 vs. 101; p<0.05); similar results are obtained considering ketorolac administration (62 vs. 71; p<0.05). CONCLUSIONS: Peritoneal lavage after gynecological laparoscopic procedures may be effective in the reduction of postoperative pain and use of analgesics.