An adaptation of the Family Stress Model was examined using structural equation modeling with data from 193 custodial grandmother-grandfather dyads. The model's measurement and structural components were largely invariant by grandparent gender. For grandmothers and grandfathers alike, the effects of their psychological and marital distress on grandchildren's adjustment difficulties were mediated by dysfunctional parenting. The effects of family-related contextual forces on grandchildren's adjustment were also indirect through direct effects on grandparents' psychological and marital distress.