Previous studies have shown that family networks evolve over time. Nonetheless, little research has linked family expansion or shrinking to the levels of available family-based social capital in older adults' family networks. To address this research gap, this paper explores the following question: to what extent are changes in family composition and family-related life events associated with current levels of family-based social capital in later years? We use the two waves of the longitudinal CIGEV-LIVES Vivre-Leben-Vivere study, a large survey addressing the family and health conditions of older people in Switzerland. We combine data on life events occurring during old age and family configurations. We find that family networks are indeed highly dynamic, with distinct patterns of losses and gains observed among respondents. Adding and omitting significant family members has distinct significant effects on social capital, while family-related life events only have marginal effects.