OBJECTIVES: In Canada, the cost of Alzheimer’s disease (AD) medications is mainly borne by patients and caregivers. The primary objective of this study was to measure the Canadian general public’s support for a program of unrestricted access to AD medications. The secondary objective was to identify determinants of support for the program.  METHODS: A national sample of 500 Canadians, aged 18 years or older, was randomly recruited to participate in a computer-assisted telephone interview. The sample was stratified by income. Participants were presented with a set of randomly-ordered scenarios describing a hypothetical, new AD medication. The efficacy of the medication was varied by scenario: the medication was alternately described as modifying the symptoms of cognitive decline or actually halting disease progression. The adverse effects profile was also varied in the scenarios: no adverse effects or a 30% chance of some adverse effects. For each scenario, participants were asked whether they supported an annual increase in personal income taxes to fund unrestricted access to the AD medication. Logistic regression was conducted to identify factors that might explain support for the tax increase.  RESULTS: Percentage of respondents supporting a tax increase varied with scenario: symptom modification and 30% chance of adverse effects=49% (n=244); symptom modification, no adverse effects=58% (n=290); halt progression and 30% chance of adverse effects=54% (n=270); halt progression, no adverse effects=67% (n=333).  Relative to the ‘symptom treatment and 30% chance of adverse effects’ scenario, the level of support was different (p<0.05) for all except the ‘halt progression and 30% chance of adverse effects’ scenario (p>0.15). No determinant (e.g., age, sex) could consistently explain support across all four scenarios.  CONCLUSIONS: Support for the tax increase varied by the efficacy and adverse effects profile of the medication. The most support was registered for the optimal scenario (halt disease progression, no adverse effects).