Forty-three case reports of patients with type 2 diabetes who were treated with insulin detemir (Levemir, Novo Nordisk A/S, Bagsvaerd, Denmark) were collected from doctors' offices for the purpose of analyzing 4 parameters: (1) effectiveness of glycemic control (fasting blood glucose [FBG] readings and glycosylated hemoglobin [A1C]); (2) tolerability (hypoglycemic episodes and weight gain); (3) dosing regimen; and (4) treatment discontinuations. Patients in the Levemir Early Clinical Experience Case Series showed improvement of mean FBG readings, with a mean decrease of 63 mg/dL from baseline by the third follow-up visit (24-41) weeks from treatment initiation). Mean A1C values decreased during this time from a baseline average of 8.6% to a final average of 7.0%. Four patients on insulin detemir reported hypoglycemic episodes, none of which required special interventions or discontinuation of treatment. A mean weight loss of 5 lb was observed at the final follow-up visit. Twenty-four (55.8%) patients were insulin-naive, and 19 (44.2%) were already on insulin at the time they were started on insulin detemir. Almost 91% of patients were on a once-daily regimen of insulin detemir; 4 patients discontinued treatment during the observation period. Overall, the observations from the Levemir Early Clinical Experience Case Series are good indicators of the early experience with insulin detemir in the United States, and are consistent with findings from controlled trials and large observational studies.