The effect of telmisartan on ambulatory blood pressure, plasma neurohormonal parameters, and oxidation of serum albumin has not been investigated in hemodialysis (HD) patients. Thirteen hypertensive HD patients were treated with 40 mg telmisartan once daily, and 24-h ambulatory blood pressure monitoring was performed after 0, 4, and 8 weeks of treatment. Plasma renin activity, plasma aldosterone concentration (PAC), brain natriuretic peptide (BNP) level, and serum oxidized albumin level were determined at the same time points. Serum telmisartan concentration was also measured at 4 and 8 weeks. Telmisartan significantly reduced systolic blood pressure and diastolic blood pressure (both awake and sleeping) after 4 weeks, and these pressures showed a further significant decrease after 8 weeks. Plasma levels of aldosterone, BNP, and serum oxidized albumin were markedly decreased after 4 weeks and these lower levels were maintained at 8 weeks. The trough serum telmisartan concentration was not significantly different at 8 weeks compared with 4 weeks. Throughout the treatment period, there were no significant adverse effects. Telmisartan effectively lowers blood pressure and reduces PAC, BNP, and oxidative stress and is safe and well-tolerated by HD patients. A long-term study in a large population is required to determine the influence of telmisartan therapy on cardiovascular mortality and morbidity in HD patients.