Prevalence of diabetes in Iran has been increased in adult population witha high proportion of poorly controlled. Information evaluating the effi cacy ofinsulin glargine for patients with type 2 diabetes were sub-optimally controlled on their previous oral antidiabetic regimen is limited in Iran. Therefore we conducted a national, multicenter non-randomized study to evaluatethe effect of glargine on control of diabetes in T2DM who were previouslyreceiving OADs. 300 patients with diagnosed type 2 diabetes less than of5 years duration and HgA1c greater than 7 who had treated at least withtwo oral anti-diabetes drugs (OADs) including Metformin and Glibenclamideenrolled. Insulin glargine were prescribed as single subcutaneous daily injection for the eligible patients. Titration and dose adjustments and decisionswere at the discretion of the physician. HgbA1C was measured at enrollment, week-12 and week 24. Glycaemic control improved signifi cantly in patients with signifi cant improvements in FBG and HbA1c.After 24 weeks themean decrease in FBG was 92.3 ± 78.8 mg/dl and in 2-h PPBG was 111.9 ±106.2 mg/dl .The mean decrease in HbA1c was 1.7% (± 1.4). It should benoticed that 54.9% of patients had HbA1c >9 at the beginning of study butat the end of study 22.4% of the subjects reached to HbA1C target of lessthan 7% and 65% had HbA1C)7.5% . The mean daily basal insulin dose atinitiation was 12.1 (SD=8.2) IU/day and increased to 20.2 (SD=9.1) IU/dayat week 24. The reported rate of all hypoglycemia episodes was less thanfi ve percent. No major and or nocturnal hypoglycemia were reported duringthe entire period of the study. The mean body weight change during thestudy was not statistically signifi cant. These results indicate that in type2 diabetes, insulin glargine at early stages was associated with signifi cantimprovements in glycaemic control.