The Incipient to Overt: Angiotensin II Blocker, Telmisartan, Investigation on Type 2 Diabetic Nephropathy (INNOVATION) study previously showed that treatment with telmisartan, an angiotensin II receptor blocker, effectively reduced the transition from incipient to overt nephropathy in Japanese type 2 diabetic patients. However, that large study included both normotensive and hypertensive patients. In the present post hoc analysis, we aimed to assess whether or not telmisartan elicits beneficial effects on the progression of microalbuminuria in normotensive patients. We randomized 163 microalbuminuric (urinary albumin-to-creatinine ratio: UACR of 100 to 300 mg/g creatinine) normotensive type 2 diabetic patients to treatment with telmisartan (40 or 80 mg once daily) or placebo over 52 weeks. The patients treated with either dose of telmisartan showed lower transition rates from microalbuminuria to overt nephropathy compared to the placebo group. In addition, more patients on telmisartan reverted to normoalbuminuria (UACR<30 mg/g creatinine): 15.5% of the 40 mg group, 19.6% of the 80 mg group, and 1.9% of the placebo group. In normotensive patients treated with telmisartan, changes in UACR were not significantly correlated with changes in blood pressure. Side effects did not differ among the groups. The present study demonstrates that telmisartan prevents the progression of microalbuminuria (in some cases induces remission of albuminuria) in normotensive Japanese patients with type 2 diabetes. Telmisartan is shown to be safe and well tolerated in these patients.