Using daily telephone interviews, 82 midlife parents (mean age = 57.4) of children with disabilities (mean age = 29.9) were compared with a closely matched sample of unaffected parents (N = 82) to elucidate the daily experience of non-normative parenting. In addition, salivary cortisol samples were obtained to examine whether parents of children with disabilities had dysregulated diurnal rhythms and the extent to which the amount of time spent with children was associated with divergent patterns of cortisol expression. We found that parents of children with disabilities had similar patterns of daily time use and similar likelihood of positive daily events as the comparison group, but they had elevated levels of stress, negative affect, and physical symptoms, all reported on a daily basis. In addition, their diurnal rhythm of cortisol expression differed significantly from the comparison group, a pattern that was strongest for parents of children with disabilities on days when they spent more time with their children. (Contains 4 tables and 3 figures.)