Introduction: Obesity is a chronic disease with increasing prevalence. Bariatric surgery has proven to be an effective method for weight reduction and decreases the prevalence of various co morbidities like diabetes, hypertension, hyperlipidoemia and obstructive sleep apnoea. Search strategy: A MEDLINE/PubMed search was conducted from 1980 until July 2009 using the search terms: obesity, bariatric surgery, critical illness, Intensive Care, Post Anaesthesia Care Unit, Medium Care and Advanced Care. Summary of findings: Four original studies and one abstract were found. The risk factors for ICU admission and prolonged mechanical ventilation were discussed. Conclusion: There are differences between Europe and the USA in the preferred type of bariatric surgery performed. There are also national and local differences between the organization and logistics of advanced care following bariatric surgery. Therefore, it is difficult to compare the literature on this subject. Almost all risk factors for advanced care admission following bariatric surgery are related to extreme weight; most of them are also related to age. Additionally, a need for extended mechanical ventilation en thus advanced care may be warranted in the following patients: males, heavier patients, those with pulmonary co morbidity and those in need of reoperation. Surgeons, anaesthesiologists and intensivists have to create clinical pathways both for the institute where they are working and their patients. © 2010, Nederlandse Vereniging voor Intensive Care. All Rights Reserved.