To examine whether the treatment of elderly hypertensives had become more aggressive over the past decade, we evaluated: (1) the frequency of new prescriptions for hypertension treatment, adjusted by age and gender; (2) the frequency with which multiple antihypertensives were prescribed concurrently within 2 years of initial diagnosis; and (3) discontinuation rates for antihypertensive therapy. We linked 4 administrative databases and a province-wide clinical database in Ontario, Canada, to derive a cohort of patients > or =66 years of age who were newly started on an antihypertensive agent between July 1, 1994, and March 31, 2002, without another indication for the agent (all patients were followed for 2 years after their initial antihypertensive prescription). Our cohort consisted of 196 451 people newly started on antihypertensive therapy, 30 433 of whom also had diabetes mellitus. The population-adjusted rate of new antihypertensive prescriptions increased by 30% between 1994 and 2002. Whereas 21% of patients newly diagnosed with hypertension in 1994 were prescribed multiple antihypertensives concurrently within 2 years of diagnosis, this proportion had increased to 40% by 2002 (P<0.0001). In the cohort of patients first prescribed an antihypertensive in 1994, 36% were not taking any antihypertensive within 2 years; only 21% of patients first prescribed an antihypertensive in 2002 had discontinued all therapy within 2 years (P<0.0001). Our data provide evidence that the physician management of hypertension in elderly Canadians became more aggressive between 1994 and 2002.