An analysis of the cost-effectiveness of simvastatin was conducted, based on the Scandinavian Simvastatin Survival Study (4S). The total cost of hospitalization in the placebo group was 52.8 million Swedish kronor (SEK) (5.15 million pounds), compared with SEK 36.0 million (3.51 million pounds) in the simvastatin group. This amounts to a 32% reduction, or a saving of SEK 16.8 million (1.6 million pounds) or SEK 7560 (738 pounds) per patient. The net cost per patient for the duration of the study (5.4 years) was SEK 13,540 (1324 pounds). Simvastatin treatment saved an estimated 0.377 undiscounted life years (0.240 life years discounted at 5% per annum). The cost of simvastatin therapy per discounted life-year saved was therefore SEK 56,400 (5502 pounds). Sensitivity analysis, examining the effect of different life expectancies, costs of initiation and monitoring of simvastatin therapy, and discount rates, showed the results to be stable. Conclusion. The cost per life-year saved of simvastatin in the treatment of post-myocardial infarction and angina patients, as determined from 4S data, is well within the range normally considered cost-effective.