OBJECTIVE: To compare the economic consequences of antihypertensive treatment with perindopril (1x 4 mg) and enalapril (2x10 mg). METHODS: The clinical, epidemiological and economic data were derived from a scientific project conducted in the whole of Poland among GPs, and concerned 438 patients treated in mono-therapy within the last year. Calculations were made from the societal perspective and the retrospective approach was applied. The direct medical costs of: pharmacological treatment, doctors' consultations, hospitalisation, laboratory and diagnostic tests were identified and calculated. Indirect costs were also assessed by the capital cost method. Effectiveness was measured by the percentage of the patients with appropriate blood pressure control according to the first definition (BP£140/90 mmHg) and the second definition, (BP<140/90 mmHg), consistent with JNC VI guidelines. RESULTS: Effectiveness, measured according to the first definition was 52,45% in the perindopril group and 41,03% in the enalapril group. According to the second definition it was respectively, 43,63% and 25,64%. Cost of the doctors' consultations in the perindopril group was lower by 16,52% than in the enalapril group, which represents a saving of €19,29 per patient per year. Indirect costs reduction in the perindopril group amounted to €131,26 per patient per year which means -54,06%. Total cost in the perindopril group, was lower by €55,44 per patient per year than in the enalapril group. Calculation of the cost-effectiveness ratios according to the first definition (Wp=1020; WE=1439) and the second definition (Wp=1226; WE=2303) revealed the treatment with perindopril as a more cost-effective than enalapril. CONCLUSION: The results of the analysis revealed significant cost reductions and better blood pressure control in the perindopril group as compared to the enalapril group. The savings in the perindopril group resulted from the reduction of the physicians' consultation costs and from the considerable reduction of the indirect costs.