ERAS is the acronym for enhanced recovery after surgery, a term often used to describe perioperative care programs that have been shown to improve outcomes after major surgery. This article gives a brief history of the development from fast-track surgery to ERAS. Today, the full meaning of ERAS goes beyond just a protocol for perioperative care with the initiation of a novel multiprofessional, multidisciplinary medical society: the Enhanced Recovery After Surgery Society for Perioperative Care (www. erassociety. org). The ERAS Society is involved in the development of evidence-based guidelines. These guidelines form the basis for an implementation program of the ERAS principles to practice. While ERAS was initially developed for colonic resections, these principles are being used in a range of operations, and there is also a continuous update of care protocols as the fields develop. A key mechanism behind the effectiveness of ERAS is the dampening of the stress responses to the surgical insult combined with the use of treatments that support return of functions that delay recovery in traditional care. The article also gives some insights to why the protocols work and reports the effects of ERAS protocols.