OBJECTIVES: The objective was to assess resource utilization before and after the development of Alzheimer’s disease (AD), using the Quebec provincial drug reimbursement program database (RAMQ). METHODS: This study included patients covered by the RAMQ who had at least one diagnosis of AD (ICD-9 code 3310) or have received at least one script for an AD medication (donepezil, rivastigmine, galantamine or memantine) from January, 1985 to December, 2011. A control group of patients without AD was created on a 1:1 ratio and matched for age, gender and geographic location. The index date was defined as the date of the first AD diagnosis or the first script for AD medication whichever comes first. Health care resource costs were analyzed in terms of emergency room, outpatient clinic, intensive care unit and physician’s visits, hospitalizations and long-term care, plus AD medications and other medications costs. Annual health care costs were reported for the 5-years before and the 5-years after the index date. RESULTS: Data were obtained for a random sample of 34,086 AD patients (mean age of 78.5 years [SD=8.0], 65.2% females). Before the index date, health care costs were similar between AD patients and the control group, except for the year preceding AD. Indeed, cost per patient for this year increased from CDN$5,126 to CDN$8,839 for the AD group and from CDN$4,466 to CDN$5,212 for the control group (72.4% vs. 16.7% increase respectively). For the 5-year period after the index date, costs were significantly higher for AD patients with an average cost per patient per year of CDN$9,364 vs. CDN$5,864 for the control group (mean difference of CDN$3,500,p<0.001). CONCLUSIONS: AD significantly increases health care resource costs, including medical resources and medications. Costs generated by AD patients cumulate over time leading to a major difference in long-term costs compared to non-AD patients.