Addition of pravastatin to dietary advice has been shown by the West of Scotland Coronary Prevention Study (WOSCOPS) to prevent the transition from health to cardiovascular disease. METHODS: An economic analysis was conducted to assess the cost-effectiveness of primary prevention with pravastatin. Appropriate Canadian risk factor data were used in an exponential regression model derived from WOSCOPS data to estimate the rates at which Canadians transition to cardiovascular disease. The number of transitions avoided were valued in terms of cost savings to the Canadian health care system, as well as life years gained. Canadian costs (1996 CAD $1=$0.72 US) were based on ICD-9-CM Ontario Case Cost Project inpatient hospital data and were discounted at 5% per annum beyond the first year. The difference between age and gender-specific Canadian life table survival and post-event survival obtained from Scottish linkage data was calculated to estimate life years gained. RESULTS: The prevention of 303 transitions to CVD, which implies 3,067 years of life gained, would be achieved if 10,000 Canadian hypercholesterolaemic men started treatment. Based on these results, cost-effectiveness ratios of $10,113/LYG (undiscounted), and $24,223/LYG (discounted) were obtained. If only high-risk patients (defined by published consensus statements) are treated, the ratios drop to between $6,865 and $16,391. CONCLUSION: In light of published Canadian economic analysis guidelines, this constitutes strong evidence for adoption of primary prevention with pravastatin to avoid the clinical manifestations of CVD.