Early insulin action is of major importance to suppress hepatic glucose production after a meal and reduce post-prandial glucose excursions. Currently available rapid-acting analogues have a faster onset and a shorter duration of action than human regular insulin which has been shown to improve post-prandial glucose excursions and overall glucose control with regard to either hypoglycaemia or HbA1c, in particular in patients using continuous subcutaneous insulin infusion (CSII). Nevertheless, the onset of action of rapid-acting analogues is still considerably slower than the profile of endogenous insulin release after meal intake. The presentation will therefore discuss if further improvements are achievable with insulins that have an even faster onset of action. It will be discussed how the characteristics of the ideal insulin for prandial coverage could look like with regard to both onset and duration of action. Pharmacokinetic and pharmacodynamic data of new, so-called ultrafast insulins will be presented and the clinical impact of these characteristics will be discussed.