Low compliance is suspected as a major reason for treatment failure in hypertensive patients. To identify patients with low compliance at the commencement of antihypertensive treatment, the compliance praxis survey (COMPASS) was utilised. A total of 161 physicians identified 2389 hypertensive patients treated by ACE-inhibitor. The physicians rated the compliance of the patients at baseline and at 6-month follow-up prospectively. Standard care was given. The mean age of patients was 64.5 years (54.4% women). The baseline overall score of compliance was medium to high in 97.3% of patients. A quarter of all patients (24.7%) were described as having difficulties to follow lifestyle changes, 22.3% lacked sufficient social support, and 31.0% were unwilling to obtain additional information about illness and treatment. Patients who had received prior treatment for cardiovascular disease were less compliant than those who received first treatment within this study (P=0.05). Younger (P<0.01), male patients (P<0.01), and those without prior cardiovascular disease (P<0.001) were significantly more likely to stop the antihypertensive treatment without a doctor's recommendation. Doctors' rating of compliance at baseline correlated well with ongoing treatment at 6-month follow-up. In conclusion, the COMPASS survey questionnaire is a useful instrument for doctors to differentiate between patients who lack resources and to then counsel patients based on their individual needs.