#### Summary points Outpatient parenteral antimicrobial therapy (OPAT) allows patients to be given intravenous antibiotics in the community rather than as an inpatient. First developed in the 1970s in the US for the treatment of children with cystic fibrosis,1 OPAT has expanded substantially and is now standard practice in many countries.2 3 In the UK, uptake has been much slower, although OPAT is now being increasingly used in both primary and secondary care, driven by a national focus on efficiency savings in healthcare, improving patient experience, and provision of care closer to home. It is important that medical practitioners are aware both of the opportunities that OPAT presents and of the potential risks of treatment outside hospital for patients with serious and often complex infections. This article aims to describe the clinical practice of OPAT, highlight potential risks, and explore how these may be reduced. OPAT is the administration of intravenous antimicrobial therapy to patients in an outpatient setting or in their own home. It can be used for patients with severe or deep seated infections who require parenteral treatment but are otherwise stable and well enough not to be in hospital; these patients may be discharged early to an OPAT service or may avoid hospital admission altogether. ### Cellulitis OPAT is most widely used …