Abstract Objective: Overt cardiovascular diseases and diabetes mellitus occuring in the population of hypertensive subjects may be a related to the effectiveness of antihypertensive treatment. Aim of the study was to obtain information concerning drug utilisation, the clinical characteristics of hypertensive patients and blood pressure control in a large population. Design and method: We performed ad observational study aimed at defining prevalence of diabetes mellitus, heart failure, chronic kidney disease, atrial fibrillation previous myocardial infarction among hypertensive patients living in the province of Verona (approximately one third of the estimated total number). Information concerning antihypertensive treatment (the number of different drugs concomitantly prescribed over a period of 12 months among 13 drug categories), age, sex, blood pressure (categorical variable, cutoff 140/90 mmHg) was collected from their electronic records (database MySQL, Centro Studi FIMMG) by the 150 General Practitioners taking part in the study. Chi-square test was used in the subgroup analysis. Logistic regression analysis was performed to define which variables were independent predictors of blood pressure control. Results: The total number of studied hypertensives was 43526 (females 52.7%), 19.3% of them also had diabetes mellitus, 9.4% atrial fibrillation, chronic kidney disease, 2.9% heart failure and 2.2% a previous myocardial infarction. Data concerning blood pressure control in the previous 12 months was available for 26949 patients (females 51.%). By logistic regression analysis, predictors of inadequate blood pressure control were, not being treated (n = 2013), female sex, coexistent diabetes mellitus and chronic kidney disease (P < 0.0001). When only patient that could ben defined as resistant to medication were considered (uncontrolled blood pressure control with 3 drugs or treated with 4 drugs or more, n = 6472), the prevalence of diabetes mellitus (32.8%), atrial fibrillation (20.1%), heart failure (9.1%), chronic kidney disease (7.8%) myocardial infarction (4.4%) was higher than in patients treated (P < 0.0001). Conclusions: In a large part of the population of hypertensives blood pressure control is not achieved. Overt cardiovascular diseases or diabetes mellitus in hypertensive patients are associated with poor blood pressure control, independently of the number of prescribed drugs, suggesting a vicious circle that could result in worsening of organ damage.