OBJECTIVE: The GREAT (GRoup on Economic Assessment of hyperTension) study has the objective to estimate the cost of care of hypertension study in Emilia Romagna region and to evaluate the degree of blood pressure (BP) control. METHODS: Twenty-seven GPs and 9 specialists centres participated in a previously reported cross-sectional part of the study. Nine GPs and 2 specialists centres completed the longitudinal section of the study. Demographic, clinical and economic information was collected. Health care provided to patients has been quantified in the perspective of the Italian National Health Service (NHS), by means of tariffs. We report on health care costs evaluated in the longitudinal section of the study. All costs are presented as monthly costs and expressed in Euros (1 € = 1936.27 ITL). RESULTS: 106 patients were assessed in the longitudinal study, 46 women (mean age 63 ± 12) and 60 men (63±10). The average follow-up period was 202±68 days and there was one death. Fifty-eight (55%) patients had comorbidities, 13 (12%) were smokers.The mean levels of SBP and DBP were 138±35 and 81±20 mmHG at inclusion and 134±31 and 79±23 mmHg at the end of the study. More than 56% of the subjects obtained a satisfactory control of BP (SBP<140 and DBP<90) and 27.4% of the patients reached an optimal control (SBP<135 and DBP<85). The average monthly cost of hypertension care per-patient over the follow-up period was 47.2€. Drugs represent the largest part of costs (30.0€, 63%), followed by physicians' visits (8.9(, 19%) diagnostics (3.2€, 7%), hospitalization (2.7€, 5%) and lab tests (2.4€, 5%). CONCLUSIONS: During the observation period the majority of patients reached a satisfactory control of BP. Drugs costs represent the most relevant cost item among health care cost, probably due to the time horizon of this study (on average seven months).