OBJECTIVES: The objective of this study is to determine alcohol-attributable fractions (AAFs) for each disease and injury category and to calculate health care costs due to the diseases caused by alcohol drinking based on health system’s perspective. METHODS: The alcohol-attributable fractions (AAFs), which are generally defined as the proportion of a disease in a population that is attributable to alcohol drinking, were calculated from 1) prevalence of alcohol drinking, 2) age and sex-specific relative risk for each disease. Pooled relative risks derived from meta-analyses were preferable for this calculation. The number of patients in each disease category that is attributable to alcohol drinking was then, calculated as the product of the AAFs and the total number of patients with specific disease, classified by sex- and- age group.  Health care cost of alcohol drinking were, further, be estimated by  multiplying the number of patients in each disease category that is attributable from alcohol drinking with cost per relative weight obtained by the National Health Security Organization. RESULTS: Health care costs attribute to alcohol incurred in outpatient department (BAHT2,294,524,869), inpatient department (BAHT2,968,785,412). Therefore, total health care cost attribute to alcohol was BAHT5,263,310,281. Fifty- six percent of total health care cost attribute to alcohol were healthcare cost in outpatient department. CONCLUSIONS: The result of this study indicated that alcohol drinking was significantly associated with a large number of health care cost in Thailand.