Answers to the question, what support exists for the elderly when needed, are often simplified as "their children", yet, there are related issues which need deeper inquiry such as the extent and scope of children's support and whether it is possible to compensate this support. Examining social and filial patterns and benefiting from task specific and hierarchical compensatory theories, this paper attempts at addressing these issues in the city of Tehran. Using a sample of 527 elderly person aged 60 and over in Tehran, the relationship between emotional, instrumental, and financial dimensions of social and filial sources of support are investigated. In the context of the second phase of the demographic transition period, the size and the sex composition of family networks among the examined elderly are found to be large for both sexes. Despite the high number of children who have migrated, there are still a significant number of them remaining children who are accessible by their parents, and the family support network is still dominated by filial support. The support that parents, especially mothers, receive from their children is not replaceable by other sources of support. However, because of similar group structures, the extended family and non-family support networks remain relevant in providing significant emotional and financial support to the elderly.