Individual dfirences in parenting stress, experienced by most parents as those aversive feelings that are associated with the demands of the parenting role, have been shown to be an important aspect of parent, child, and family functioning. A definition of parenting stress is provided, along with its application t o more general stress models. Three implicit hypotheses in much of the past research on parenting stress and behavior am evaluated (a) parenting stress is causally related t o poor parenting, (b) poor parenting is causally related to problems in child adjustment, and (c) parenting behavior mediates the associations between pamnting stress and child adjustment. In addition, three quertions for future research regarding wlthin-family and within-indhridual variation in parenting stress are raised: (a) Is parenting stress genetiully influenced? (b) Do mothers and fathers show similar or different levels of parenting stress? (c) Is parenting stress 'child speclfic" within families?