Treatment intensification in people with type 2 diabetes following failure of basal insulin commonly involves the addition of a rapid-acting insulin analogue (basal plus one or more prandial doses; multiple daily injections) or by a switch to premixed insulin. Insulin degludec/insulin aspart (IDegAsp), comprising rapid-acting insulin aspart and ultra-long-acting insulin degludec in solution, enables both fasting and post-prandial glucose control, with some advantages over other treatment intensification options. These include straightforward dose titration, flexibility in dose timing, low injection burden, simplicity of switching and a lower risk of hypoglycaemia. In Australia, where insulin degludec on its own is not available, IDegAsp enables patients to still benefit from its ultra-long-acting properties. This review aims to provide guidance on where and how to use IDegAsp. Specifically, guidance is included on the initiation of IDegAsp in insulin-naïve patients, treatment intensification from basal insulin, switching from premixed or basal-bolus insulin to IDegAsp, up-titration from once- to twice-daily IDegAsp and the use of IDegAsp in special populations or situations.