Patients undergoing laparoscopic cholecystectomy experience sever referred pain postoperatively. They usually require more analgesic consumption and long-term hospital stay, which consequently result in higher costs. Thus, this study is aimed to investigate the effect of acetazolamide and paracetamol on referred pain of candidate patients for laparoscopic cholecystectomy, and to find a cost-effective way to reduce pain. In a randomized, controlled, double blinded trial, 114 adult patients with uncomplicated cholelithiasis undergoing laparoscopic cholecystectomy will be evaluated with regard to postoperative referred pain. Patients are randomly assigned to 3 groups to receive 250 mg acetazolamide, 1 gr paracetamol or placebo. In case of any complications, such as ductal damage, bile leakage, biliary ascites or excessive bleeding during surgery, or if the surgeon has to insert a drain at the end of operation, then those patients are excluded from study. The postoperative pain will be assessed according to the location, intensity and type of pain, immediately before and after surgery, after return of consciousness, at the time of stay in post-operative care unit, during 24 hours stay in the ward and at the time of discharge. Also, the patients’ demographic data such as age and gender, the dose and kind of analgesic will be documented.