['Aim of this prospective study was to determine whether patients with a higher body mass index (BMI) will benefit more from laparoscopic procedures in respect to postoperative morbidity and pain as compared to regular patients.', 'Between September 1999 and October 2001, we performed 36 laparoscopic radical nephrectomies and 18 nephron sparing partial nephrectomies for renal cell carcinoma and 6 nephrectomies for benign disease (group 1, n=60). In addition, we performed 24 open radical nephrectomies and 18 nephron spearing interventions for renal cell carcinoma (group 2, n=42). Mean age was 59+/-17.9 years and average BMI was 27.1+/-3.3 kg/m(2) in the entire group. All techniques were evaluated for intraoperative results and complications. Postoperative morbidity was assessed in all patients by quantifying pain medication and by daily evaluation of Visual Analogue Scale (VAS).', 'Mean hospitalisation time in group 1 as compared to group 2 was 10.1 days versus 5.4 days, average operating time was 273 minutes versus 187 minutes, mean length of skin incision was 7.2 cm versus 30.8 cm. Overall analgesic consumption was lower in the laparoscopic group (190 mg versus 590 mg, p<0.001), in patients with a BMI >28 kg/m(2) the difference was even more pronounced (160 mg versus 210 mg, p=0.032). In group 1, patients with a BMI >28 kg/m(2) had significantly less pain on the first and fourth postoperative day in a linear regression analysis (VAS1=10.714-0.218 BMI; r=0.688 (p<0.001) and VAS4=3.98-0.09 BMI, r=0.519 (p<0.001), respectively). In group 1, 3/60 (5.0%) and in group 2, 5/42 (11.9%) complications occurred, no difference was found in respect to a high BMI (p=0.411).'] Are benefits of laparoscopic renal surgery more pronounced in patients with a high body mass index?