Blood pressure levels are strongly predictive of the risks of first-ever and recurrent stroke. The benefits of blood pressure-lowering therapy for the prevention of fatal and non-fatal stroke in middle-aged individuals are well established. However, until recently, there has been uncertainty about the consistency of such benefits across different patient groups and in particular, for older people and in those with a history of stroke. This paper discusses the evidence surrounding the effectiveness of blood pressure-lowering therapy, specifically in older patients with a history of stroke, with particular attention paid to the results from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS). PROGRESS was a randomised, double-blind, placebo-controlled trial of 6105 individuals with a history of cerebrovascular disease recruited from 172 hospital outpatient clinics in ten countries. Participants (mean age 64 years; range 26-91 years) were randomly assigned to receive active treatment with an ACE inhibitor-based blood pressure-lowering regimen (perindopril) with or without addition of the diuretic indapamide, or matched placebo. At the end of follow up (mean of 4 years), active treatment reduced the incidence of total stroke by 28% (95% CI 17-38%) and the rate of major vascular events by 26% (95% CI 16-34%). Importantly, benefits of treatment were consistent across key patient subgroups, including those with and without hypertension, patients who were Asian and non-Asian, and for both ischaemic and haemorrhagic strokes subtypes. Current evidence is now strong for clinicians to consider blood pressure-lowering therapy as pivotal in the prevention of stroke, especially in patients with a known history of cerebrovascular disease (and vascular disease, in general), irrespective of blood pressure levels, as soon as patients are clinically stable after an acute stroke or other vascular event. Additional age-specific analyses of the PROGRESS data, together with those from other completed trials, will provide more reliable information about the size of the benefits of blood pressure-lowering therapy, specifically for different age groups, and particularly in the oldest old (those aged >80 years). In the meantime though, an ACE inhibitor plus diuretic treatment regimen that maximises the degree of blood pressure reduction has a good safety profile and is an effective treatment that should be considered in all patients with stroke, including the elderly.