Insulin degludec/insulin aspart (IDegAsp) is the first soluble coformulation combining a long-acting insulin degludec (IDeg) and rapid-acting insulin aspart (IAsp). In patients with uncontrolled type 2 diabetes (T2DM) previously treated with insulins, IDegAsp twice daily effectively improves glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels with fewer hypoglycaemic episodes versus premix insulins. Further, insulin initiation with IDegAsp once daily provides superior long-term glycaemic control compared to insulin glargine with similar FPG and insulin doses, and numerically lower rates of overall and nocturnal hypoglycaemia. In patients with type 1 diabetes mellitus (T1DM), IDegAsp once daily and IAsp at remaining meals provides more convenient three injection regimen per day over conventional 4-5 injections based basal-bolus therapy. IDegAsp is an appropriate and reasonable option for intensifying insulin therapy in patients with T2DM and a relatively less complex treatment option for the management of T1DM.