Ambulatory surgery can be carried out in diabetic patients. By using a strict organisational and technical approach, the risk of glycaemic imbalance is minimised, allowing the patients to return to their previous way of life more quickly. Taking into account the context of ambulatory surgery, with a same day discharge, the aims are to minimise the changes to antidiabetic treatment, to maintain adequate blood sugar control and to resume oral feeding as quickly as possible. The preoperative evaluation is the same as for a hospitalised patient and recent glycaemic control (HbA1c) is necessary. Perioperative management and the administration of treatment depend on the number of meals missed. The patient can return home after taking up usual feeding and treatment again. Hospitalisation is necessary if significant glycaemic imbalance occurs. In pregnancy, it is necessary to distinguish between known pre-existing diabetes (T1D or T2D) and gestational diabetes, defined as glucose intolerance discovered during pregnancy. During labour, blood sugar levels should be maintained between 0.8 and 1.4 g/L (4.4–8.25 mmol/L). Control of blood sugar levels is obtained by using a continuous administration of insulin using an electronic syringe (IVES) together with a glucose infusion. Post-partum, management depends on the type of diabetes: in T1D and T2D patients a basal-bolus scheme is restarted with decreased doses while in gestational diabetes insulin therapy is stopped after delivery. Antidiabetic treatment is again necessary if blood sugar levels remain > 1.26 g/L (7 mmol/L).