The aim of the project is to assess the quality and improve the preventive and curative practices at the primary care level in Hungary. A total of 50 general practitionaires were selected on a voluntary basis in Budapest, Hungary, and from them, 30 were randomized to the intervention (I) group and 20 to the reference (R) group. The members in the I group have been trained for the official hypertension guideline and their everyday work is monitored. Those in the R group have only been monitored to measure the efficacy of the training. In all, 10% from the known hypertensive persons (N=10,799) and 5% of the remaining (nonhypertensive) patients (N=60,341) were selected randomly from the GP's computer files and invited for screening investigation performed by trained medical students. They measured the blood pressure of patients, assessed the cardiovascular risk status and the quality of education of patients by standardized questionnaires. In total, 4083 patients were invited, but only 39.2% attended the screening visit. The prevalence of undetected hypertension was 34.6%. This prevalence was significantly higher in the older (>60 years: 46.8%) than in the younger (<50 years: 20.8%, P<0.0001) age group and it was higher in men (41.5%) than in women (30.1%, P<0.001). The proportion of H patients on drug treatment was 85.3% and the frequency of patients under effective blood pressure control (eg<140/90 mmHg) was 27.8%. Counselling to patients for a healthier lifestyle (exercise, smoking, alcohol consumption, diet) was very rare. In conclusion, our data represent the primary care of Budapest and may not be relevant to the whole country. As a consequence of this study, education of primary care physicians and patients is a must for further improvement of hypertension care.