Given the socio-economic changes in recent decades and the need to examine intergenerational relationships, this study examines the various dimensions of adult children's support of parents, including instrumental support, emotional support and financial support. The statistical population of this cross sectional survey was men and women aged 18 years old and above in Tehran who had at least one living parent and non-coresident. A thousand men and women were selected by multi-stage clustering sampling from 30 districts. The findings have shown that adult children's support with their parents was not the same in different dimensions, so as emotional support for parents was greater than instrumental support, especially financial support. The factors influencing adult children's support of their parents are not the same in different dimensions and has been influenced by the socioeconomic characteristics, resources, needs, and barriers in parents and adult children. Instrumental support affected by parental age, living arrangements, adult children's religiosity, child committment, geographical distance; emotional support affected by adult children's religiosity, filial obligation, parental conflict, conflict with parents; financial support affected by the age of the parents, the welfare of adult children, child commitment, conflict with parents, geographical distance. These findings confirm the theories of altruism, intergenerational and contingent solidarity.