Cost-effectiveness of secondary prevention of CHD in Western World with simvastatin (S) is well established. OBJECTIVE: Cost-effective evaluation of secondary prevention of CHD with simvastatin in Polish settings with the health care system in transition period. METHOD: It was assumed that effects of S in Polish patients would be the same as those of Scandinavian Simvastatin Survival Study. Direct medical costs were obtained from Polish sources. ICER was calculated dividing net costs by years of life gained during 5.4 years of treatment with S projected over average life expectancy of 10 years. One-way and multi-way sensitivity analysis were performed. Frequency of hospitalisations, costs of hospitalisations, and life-years saved were the variables used in Monte Carlo analysis. RESULTS: Net cost/patient (discounted at 5%) was $ 2 478.5; cost per life-years saved (LYS) was $ 10 326.8 (mean ICER from Monte Carlo analysis was $ 10 243.9). ICER value was highly sensitive to the price of S and relatively insensitive to the value of savings (including saving of PTCA, CABG, myocardial infarction, and hospitalisations). The latter, in Polish settings, amouted to only 8.2% of drug`s cost (in Sweden ~ 30%). The cost of LYS is higher than the cost of 1 year hemodialysis and about 3 times higher than GNP per capita ($ 3 527.6) in Poland. CONCLUSIONS: Results indicate that secondary prevention of CHD in patients, with mild hypercholesterolemia, with S in Poland is hardly cost-effective due to tha low value of savings. The value of medical services are in Poland probably underestimated.