OBJECTIVE To study the associations of patient-related and perceived healthcare-related factors with the control of blood pressure. METHODS Physicians identified all of the hypertensive patients they saw during I week in 26 health centres. Out of 2,219 patients, 80% agreed to participate, 88% of which took antihypertensive medication. METHODS In this cross-sectional questionnaire study, based on 82 opinion statements, 14 problem indices were formed using factor analysis. Logistic regression models were used to study the associations with blood pressure control. RESULTS Eighty per cent of the men and 79% of the women had poor blood pressure control (BP > or = 140/90 mmHg). High levels of hopelessness towards hypertension (adjusted OR 2.16; 95% confidence interval (CI) 1.20-3.88) as well as medium and high levels of frustration with treatment (adjusted OR 1.50; 95% CI 1.04-2.18 and OR 1.83; 95% CI 0.98-3.44) were associated with poor control. The perceived tension with blood pressure measurement (adjusted OR 1.60; 95% CI 1.08-2.36) was similarly associated with poor control. Non-compliance in men, old age and monotherapy were also associated with poor blood pressure control. CONCLUSIONS Hopelessness, frustration with treatment, and perceived tension with blood pressure measurement are associated with poor blood pressure control.