Midlife adults report greater investment in their children than in their parents, and these ties have important implications for well-being. To date, little research has addressed daily experiences in these ties. The present study examines daily experiences (negative and positive) with aging parents and adult children and their associations with daily negative affect and diurnal cortisol rhythms. Participants were middle-aged adults (N = 156; 56% women) from Wave 2 of the Family Exchanges Study, conducted in 2013, who completed a 7-day daily diary study, which included assessments of daily negative and positive social encounters and negative affect, and 4 days of saliva collection, which was collected 3 times a day (upon waking, 30 min after waking, and at bedtime) and assayed for cortisol. Multilevel models revealed that individuals were more likely to have contact with adult children than with parents but more likely to have negative experiences (negative interactions, avoidance, negative thoughts) with parents than with adult children. Nevertheless, contact and negative experiences with adult children were more consistently associated with negative affect and daily cortisol patterns than were interactions with parents. Findings are consistent with the intergenerational stake hypothesis, which suggests that individuals have a greater stake in their children than in their parents. Indeed, negative experiences with adult children may be more salient because tensions with adult children occur less frequently than do tensions with parents.