To describe the prevalence of activities of daily living (ADL) dependence and medical conditions and the relationship between illnesses and ADL performance in the older population of Shanghai, China. Probability sample survey of community residents. The Jing An district of Shanghai, China. The interviews were carried out at the homes of the older persons. There were 3763 noninstitutionalized elders screened, 3745 of whom completed the interview. The dependent variables were the five basic ADL items: eating, dressing, transferring, toileting, and bathing. The independent variables were dementia and 19 self-reported medical conditions, along with age, gender and education level. Of those in Shanghai aged 65 and older, 8.28% (6.52% of males, 9.17% of females) were functionally dependent in one or more ADLs. The most prevalent self-reported illness was cardiovascular disease, including hypertension (29.12%) and heart disease (26.65%). ADL performance was associated with dementia and a number of medical conditions in univariate analysis. The best predictors of functional dependence in both age groups (65-74 years; 75 years and older), based on the multiple logistic regression analysis and after controlling for age, gender, and education, were stroke, dementia, Parkinson's disease, diabetes, and emphysema. The authors have successfully applied five ADL items selected and culturally adapted from Older Americans Resources and Services to the study of older Chinese. A consistent and reliable estimate of functional dependence among older persons is obtained. The prevalence of dementia and many self-reported illness, as well as the ADL status by medical condition, are reported. The findings reveal certain patterns of relationship between illness conditions and ADL performance.