We present evidence on whether and how a household's behavior is influenced by the presence and characteristics of its extended family. Using household panel data from the Progresa program in rural Mexico, we use information on the paternal and maternal surnames of heads and spouses in conjunction with the patronymic naming convention to identify the inter and intra generational family links of each household to others in the same village. We then exploit the randomized research design of the Progresa evaluation data to identify whether the treatment effects of Progresa transfers on various household outcomes, vary according to the presence and characteristics of extended family.