OBJECTIVE: To asses the economic consequences of antihypertensive treatment with perindopril and enalapril in the elderly, from the third-party payer perspective. METHODS: The clinical, epidemiological and economic data were derived from a scientific project conducted among GPs' in the whole of Poland, and concerned 159 patients over 65. treated in mono-therapy within the last year. Calculations were made from the third-party payer perspective. The retrospective approach was applied. The direct medical costs of: drug reimbursement, physicians’ consultations, hospitalisation, laboratory and diagnostic tests were identified and calculated. Effectiveness was measured by the percentage of the patients with appropriately controlled blood pressure (BP<140/90 mmHg) in accordance with JNC VII guidelines. RESULTS: The measured effectiveness of the mono-therapy was 43% in the perindopril group and 24% in the enalapril group. Cost of the hospitalisation in the perindopril group was 54.95% lower than in the enalapril group, which is equivalent to 89.52€ saved per patient per year. Physicians’ consultations cost reduction in the perindopril group amounted to 15.18€ (21.59%) per patient per year. There was no significant difference in the costs of laboratory and diagnostic tests between the compared treatments (30.93€ and 27.28€ respectively). Treatment with perindopril requires additional payer’s expenditure of 18.95€ per patient per year. Total costs measured from the third-party payer perspective in the perindopril group, were 30.08% lower than in the enalapril group which equalled 82.10€ saved per each patient per year. CONCLUSION: Taking third-party payer perspective into consideration, mono-therapy with perindopril is superior to treatment with enalapril in elderly patients due to better blood pressure control and essential savings resulting mainly from the reduction of both hospitalisation and physicians’ consultation costs.