OBJECTIVE: To assess the association between cigarette smoking and hip fracture by using the Korea Pharmacoepidemiology Cohort(KPEC). BACKGROUND: Hip fracture is known as one of the major health problems because of its high incidence and serious consequences in the elderly people. Cigarette smoking, old age, female and low body weight have been reported as risk factors for osteoporosis which is regarded as one of the risk factors for hip fracture. But the relationship between cigarette smoking and hip fracture has not been directly evaluated yet. So we conducted a prospective cohort study to investigate the relationship between cigarette smoking and hip fracture in the Korean elderly. DESIGN: Prospective cohort study on the 8,994 elderly person aged 65 or more in Pusan, Korea between 1993 to 1996. METHODS: The Korea Phamacoepidemiology Cohort(KPEC) has been constructed with three kinds of data sources. One is from the Korea Medical Insurance Corporation; Medical Insurance Claims Database and Enrollee's Database. Other sources are from directly constructed pharmacy database and questionnaire data. incidence density and relative risk of smoking for hip fracture were estimated by using the KPEC database. Age and gender specific incidence density was calculated by dividing the number of hip fracture cases by person-years of the follow-up the cohort. Relative risks and their confidence intervals were computed by using multiple logistic regression by Windows version SAS 6.12. RESULTS: The level of incidence density in female was higher than that in male, which was increasing with age in both gender. In the multivariate analysis, we observed significant relationship between soking and hip fracture in female(PR=1.94(1.01-3.76)) in the larger amount smoking group, after adjusting for the confounders; age, alcohol drinking, medication history, physical activity and body mass index, the relative risk became slightly decreased to 1.70(0.84-3.46). CONCLUSION: Accoding to this result, we suggest that effective anti-smoking campaign should be established as soon as possible for the Korean elderly women.