Background: In the UK those paid to support adults with intellectual disabilities must manage two potentially conflicting duties that are set out in policy documents as being vital to their role: protecting service users (their duty of care) and recognising service users' autonomy. This study focuses specifically on the support of people with the genetically determined condition, Prader-Willi syndrome (PWS). Due to the behaviours associated with PWS, the support of this group of people vividly illustrates the tension between respect for autonomy and duty of care. This article explores how support workers working in a residential group home managed their competing duties of managing risk and promoting independence in practice. Methods: An ethnographic study, comprising of qualitative observations, semi-structured interviews and documentary analysis, was undertaken to investigate the work of support workers in a UK residential group home specialising in the support of adults diagnosed with PWS. The study focused on how support workers attempted to reconcile the tension between protecting service users from the risks associated with the syndrome and acknowledging service users' autonomy by enabling independence. Results: Findings demonstrate that risk was central to the structure of care delivery at the group home and support workers often adhered to standardised risk management procedures. The organisation also required support workers to promote service users' independence and many thought acknowledging service users' autonomy through the promotion of their independence was important. To manage tensions between their differing duties, some support workers deviated from standardised risk management procedures to allow service users a degree of independence. Conclusions: There is a tension between the duty of care and the duty to recognise autonomy at the level of service delivery in residential homes. Support workers attempt to manage this tension; however, further work needs to be done by both residential services and policy makers to facilitate the reconciliation of the duty of care with the duty to recognise service users' autonomy in practice.