["Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Obesity is a common and growing problem in industrialized countries, and metabolic syndrome has been the focus of much attention recently, particularly with respect to obesity. Obesity is thought to be a major factor influencing surgical complexity during abdominal surgery, including laparoscopic surgery. In this study, we focused on visceral obesity which has been recognized as the most important pathogenic factor in metabolic syndrome. We found that a high visceral fat area was a significant risk factor for a prolonged operating time. We believe that visceral obesity may greatly affect surgical complexity and may be a suitable index for predicting the degree of operating difficulty associated with laparoscopic nephrectomy.", '• To examine the impact of visceral fat on surgical complexity in patients undergoing laparoscopic nephrectomy.', '• We reviewed the medical records of 121 patients who underwent laparoscopic nephrectomy from 2006 to 2010 at our institution. • The total fat area, visceral fat area (VFA) and subcutaneous fat area were measured at the level of the umbilicus using computed tomography (CT). • To identify the type of obesity, we divided VFA into ≥ 100 cm(2) and <100 cm(2). A VFA ≥ 100 cm(2) was used as the definition of visceral obesity. • We evaluated the impact of the VFA on technical difficulties encountered during laparoscopic nephrectomy by measuring operating time.', '• A significant correlation was observed between body mass index (BMI) and operating time (P < 0.001, r = 0.316) in the patients undergoing laparoscopic nephrectomy. • VFA was also significantly correlated with operating time (P < 0.001, r = 0.348), and the correlation coefficient of VFA was higher than that of BMI. • Multivariate analysis showed that a high VFA was an independent risk factor for prolonged operating time (P = 0.009, odds ratio; 3.70), whereas BMI was not found to be a risk factor.'] Is visceral obesity a strong predictor of perioperative outcome in patients undergoing laparoscopic radical nephrectomy?