Very little is known of the longitudinal changes that occur in contact with children and participation in social activities during late-life widowhood. Using data on social networks and activities drawn from the Australian Longitudinal Study of Ageing, trajectories of change in social engagement were modeled for 1,266 participants (mean age 76.7 years) over a 16-year period. Levels of social engagement were found to remain high during older age and rose following the transition to widowhood. Frequency of phone contact with children and participation in social activities were higher for widowed than married participants. However, the very-old, males, those in lower socio-economic groups, in poorer health, or without a child living nearby were found to have lower levels of social engagement in widowhood, and may be at increased risk of social isolation. High levels of social engagement during widowhood may assist individuals in successfully over coming the challenges of spousal bereavement. (Contains 2 figures and 2 tables.)