This dual-institutional prospective, randomized pilot trial was conducted during 2009 obtaining information on the power and sample size needed for a planned multicenter randomized control trial. Our results showed that Quality of life data concerning LESS cholecystectomy are somewhat controversial: cosmetics and SF36 role emotional parameter significantly improved, no differences were found in length of hospital stay, early postoperative pain (same day of surgery) was higher but no impact on need for pain-relieving medications was found. Altman nomograms were used again to calculate the presumed sample size of an actual RCT based on the differences found on our initial results. With a significant criterion set at 0.05, using a two-tailed test, the number of patients per group, required to have a 90% power in this multicenter RCT is ~180 patients.