A double blind randomized trial, performed In 29 patients with isolated Systolic Hypertension (ISH), who lived in a older community. They had a mean age of 77 ± 9.S years. The study tried to evaluate the antihypertensive effect of oral sustained release Isosorbide dinitrate formulation (ISDN) 2D-40 mg administered twice dally vs. placebo, all patients receiving also non pharmacological treatment. After 8 weeks of therapy, supine systolic blood pressure (SBP) decreased from 177± 10 ta 146 ± 16 mmHg with ISDN (p 0.05).These results appeared as soon as the first week of treatment with ISDN. No significant differences in diastolic blood pressure or side effects occurred during the same period. This study provides evidence that ISDN Is effective and safe for reducing SBP in ISH elderly patients.