This paper examines the patterns and determinants of four types of support provided by adult children to their parents, with particular attention to differences in the helping behaviors of sons and daughters. The data come from the 1989 wave of the Survey of Health and Living Status of the Elderly in Taiwan. The analysis is based on 12,166 adult children from 2,527 families. We find that usually only one child in a family provides help with activities of daily living (ADLs) or instrumental activities of daily living (IADLs), but for financial or material support the responsibility is likely to be shared among siblings. Sons generally carry the major responsibility for taking care of their older parents, and daughters fulfill the son's roles when sons are not available.