The goal of the current study was to provide the first investigation of whether appraisals of parental marital conflict mediate associations of family income with emerging adult psychological adjustment and diurnal cortisol production. Participants were 178 college students who provided 3 saliva samples across the day and reported their family income, adjustment (depressive symptoms, perceived daily stress, internalizing problems, and externalizing problems), and appraisals of their parents' conflict (including perceptions of frequency, intensity, resolution, stability, as well as perceived threat and self-blame for conflict). Results indicated that emerging adults from low-income families reported more-negative conflict appraisals, which in turn predicted lower levels of adjustment; there was no association between income and patterns of cortisol production across the day. However, emerging adults who felt responsible for their parents' conflict displayed cortisol levels that were lower early in the day, with a tendency toward blunted cortisol slopes across the day; those who appraised their parents' conflict less negatively displayed a more normative pattern of cortisol production. These results suggest that effects of family income on psychological adjustment are explained, in part, by appraisals of parental conflict, particularly of appraisals of conflict as threatening, whereas self-blame conflict appraisals have main effects on cortisol, and predict a dysregulated and potentially maladaptive pattern of cortisol production across the day for emerging adults.