This study examined whether grandparents perceive adult grandchildren as frequent and important contacts by analyzing network membership. It additionally examined whether this network membership is related to relationship intensity during childhood. Network membership was assessed in 1992 (397 grandparents, 1,594 adult grandchildren) and at the 2005-2006 follow-up (155 grandparents, 429 adult grandchildren) from the Longitudinal Aging Study Amsterdam. Relationship intensity during childhood was assessed in 1992. One out of 4 grandparents identified at least 1 adult grandchild in their personal network. Adult grandchildren who had an intense relationship with their grandparents during childhood were more often in grandparents' network than others. An intense relationship during childhood promotes continuation of the relationship into adulthood and might contribute to grandparent's support potential. © 2011 IARR.