OBJECTIVES: Insulin degludec (IDeg) is an ultra-long acting basal insulin analog whose safety and efficacy, while reaching similar HbA1c to insulin glargine, has been established in randomized control trials. The current study aims to describe the clinical effectiveness of IDeg in insulin treated patients with type 2 DM (T2DM) switching from other insulins to IDeg in a real world setting. METHODS: Included in this retrospective cohort study were T2DM patients from Maccabi Health Services (MHS) in Israel, mainly treated by basal insulin with or without bolus prior to IDeg initiation for at least one year. HbA1c and weight were measured at baseline (180 days pre-switch) and at 6 months of IDeg therapy (±90 days). RESULTS:  A total of 211 eligible patients were identified, 57 % were males, mean age was 62.2 years (SD=12.1) and all patients had diabetes duration of > 10 years. Switch to IDeg led to a mean decrease in HbA1c of 0.58% (SD=1.0, P<0.001) from a mean baseline of 8.8% (SD=1.5). Baseline HBA1c of > 8.5% and daily insulin dose of ≥ 50 units were associated with a greater reduction in HbA1c (1.00% (SD 1.11) and 1.24% (SD 1.09), respectively). The mean basal insulin daily dose increased by 2.04 units (SD=16.71) compared to pre switch insulin dose. The dose increase was driven by an increased dose in the first 90 days after index date. Hereafter a return to the baseline insulin dose level was observed. There was no significant weight change and of as for health expenditure there was a small increase in visits to diabetes specialist and use of self-blood glucose measurement sticks. CONCLUSIONS:  In a real life setting, switch from another insulin to IDeg significantly improved glycemic control in Type 2 DM patients with no significant weight gain and only a minor initial dose increase after IDeg initiation.