Objective: To estimate the smoking attributable medical expenditures and productivity loss of people aged 35 and over in Taiwan in 2001 from a societal viewpoint. Methods: A prevalence based approach was used to estimate smoking attributable costs. Epidemiological parameters were obtained from two follow up studies and government statistics. Data on medical care utilisation and expenditure were extracted from the National Health Insurance claim data. Results: Total smoking attributable medical expenditures ( SAEs) amounted to US$397.6 million, which accounted for 6.8% of the total medical expenditures for people aged 35 and over. Mean annual medical expenditures per smoker was US$70 more than that of each non-smoker. Smoking attributable years of potential life lost ( YPLL) totalled to 217 761 years for males and 15 462 years for females, and the corresponding productivity loss was US$1371 million for males and US$18.7 million for females. Conclusion: Medical expenditures attributable to smoking accounted for 6.8% of the total medical expenditure of people aged 35 and over for the year 2001 in Taiwan. Corresponding YPLL and productivity loss also demand that actions be taken to fight cigarette smoking.