Patients are diagnosed as having chronic kidney disease (CKD) if estimated glomerular filtration rate (eGFR) is <60 mL/min/1.73 m2. Low eGFR is likely to increase the incidence of cardiovascular events and lead to dialysis. Therefore, it is important to prevent eGFR from decreasing eGFR. However, it still remains unknown whether antihypertensive therapy can prevent low eGFR from becoming even lower and improve eGFR in hypertensive patients with CKD. The authors analyzed the results of the Japan Multicenter Investigation for Cardiovascular DiseaseB (JMIC-B) and investigated the effects of antihypertensive therapy on eGFR. In hypertensive patients with CKD (eGFR <60), eGFR was significantly increased from 51.87±6.21 (n=98) to 57.55±19.00 (P<.001) after 3 years of antihypertensive therapy. In patients without CKD (eGFR ≥60), eGFR was significantly decreased from 91.84±23.27 (n=682) to 88.95±23.67 (P<.001). Regardless of the type of antihypertensive drugs used, eGFR was significantly increased in patients with CKD and was significantly decreased in patients without CKD. This paper shows that antihypertensive therapy can improve eGFR in hypertensive patients with CKD. J Clin Hypertens (Greenwich). 2012;00:00–00. ©2012 Wiley Periodicals, Inc.