These Joint British Diabetes Societies guidelines, commissioned by NHS Diabetes, for the perioperative management of the adult patient undergoing surgery are available in full in the Supporting Information. This document goes through the seven stages of the patient journey when having surgery. These are: primary care referral; surgical outpatients; preoperative assessment; hospital admission; surgery; post-operative care; discharge. Each stage is given its own considerations, outlining the roles and responsibilities of each group of healthcare professionals. The evidence base for the recommendations made at each stage, discussion of controversial areas and references are provided in the report. This document has two key recommendations. Firstly, that the management of the elective adult surgery patients should be with modification to their usual diabetes treatment if the fasting is minimized because the routine use of a variable rate intravenous insulin infusion is not recommended. Secondly, that poor preoperative glycaemic control leads to post-outcomes and thus, where appropriate, needs to be addressed prior to referral for surgery.