The efficacy of antihypertensive drug therapy is undisputed, but observational studies show that few patients reach a target blood pressure <140/90 mm Hg. However, there is limited data on the drug prescribing patterns and their effectiveness in real practice. This retrospective observational survey of electronic patient records extracted data from 24 Swedish primary health-care centres, with a combined registered population of 330 000 subjects. We included all patients > 30 years with a recorded diagnosis of hypertension who consulted the centres in 2005 or 2006 (n=21 167). Main outcome measures were systolic and diastolic blood pressures, and prescribed antihypertensive drug classes. Only 27% had a blood pressure <140/90 mm Hg. The number of prescribed drugs increased with age, except among the oldest (> 90 years). Only 29% of patients given monotherapy had a blood pressure <140/90 mm Hg. Women more often received diuretics (52 vs 42%), and less often angiotensin-converting enzyme inhibitors (22 vs 33%) and calcium channel blockers (26 vs 31%) than men. β-Blockers and diuretics were the most common drug classes prescribed, independent of comorbidity. In conclusion, one out of four primary care patients with hypertension reach target blood pressure. More frequent use of drug combinations may improve blood pressure control.