This research investigates the conceptualization and application of the family fundamental interpersonal relations orientation(FIRO) model to an at-risk family population. The relationships between the family FIRO domains of inclusion, control, and intimacy and family functioning indices, as measured by the Family Assessment Device (FAD) subscales, were explored. An at-risk family population ( N = 43 primary caretakers) was assessed at four time intervals, using an ex post facto design with multiple linear regression model testing. The results indicated significant relationships between FIRO model domains and FAD subscales. A case example further explored the application of the family FIRO model with at-risk families.