Patients were also three times more likely to be admitted to hospital after a non-fatal stroke.
Experts said it was vital patients take their BP medication to avoid the risks of a potentially fatal stroke. They warned that non-adherent patients face a greater risk for up to 10 years.
The study, by researchers at the University of Helsinki, Finland, and University College London, is the first to examine the long-term risk of stroke from non-adherence to antihypertensive drugs.
Although antihypertensive drugs are commonly used to prevent a stroke, few studies have considered the risks of not taking prescribed BP medicines over several years.
Researchers looked at the medical records of 73,527 hypertensive patients in Finland who had been prescribed BP drugs. These patients were aged 30 years or over and had no history of stroke or cardiovascular event. A patient was adherent if they collected at least 80% of their prescriptions.
Researchers found that 2,144 patients died from stroke and 24,560 were hospitalised due to the condition over the course of 10 years.
Non-adherent patients were 3.8 times more likely than those who took the drugs to die from a stroke two years after they were first prescribed antihypertensives, and three times more likely after 10 years.
The risk of hospitalisation after a stroke was 2.7 times higher two years after treatment began and 1.7 times higher at 10 years.
As adherence worsened, so did stroke risk. Patients who took only 30-80% of prescribed drugs for two years had a 3.3-fold extra annual risk of stroke. Among patients with adherence of under 30%, this rose to a 7.5-fold increased risk.
Lead author Dr Kimmo Herttua of the University of Helsinki said: 'These results emphasise the importance of patients taking their antihypertensives correctly to minimise their risk of serious complications.'