Diabetic kidney disease (DKD) is the main cause of end-stage renal disease (ESRD). The use of insulin represents a challenge in patients with DKD due to the patient and medication issues. Insulin regimens, insulin dosing, and titration need to be individualized based on the patient's age, renal function, and comorbidities to improve glycemic control and reduce the risk of hypoglycemia. Insulin is the primary treatment in all patients with type 1 diabetes mellitus (T1DM) and DKD. For patients with type 2 diabetes mellitus (T2DM) and early stage of DKD, basal insulin combined with oral antidiabetic drugs (OADs) is recommended. In patients with middle and advanced DKD, it is necessary to adjust the dose of insulin according to stages of DKD, and the use of insulin analogs is recommended. In particular, elderly patients with DKD can simplify their insulin regimen to reduce the risk of hypoglycemia. In pregnant women with DKD, insulin requirements also vary based on parity and the stage of pregnancy.