Objectives: Research suggests pets and the human–animal bond (HAB) play significant roles in the health and mental health of family members. Critiques of measures used in HAB research have noted the need for research on the validity and reliability of HAB measures. This study was a validity study of scores on the Family Bondedness Scale (FBS). Methods: Multigroup confirmatory factor analysis methods were used to test the measurement equivalence and convergent validity of FBS scores for female and male pet owners. Results: Results were consistent with configural, metric, and near full threshold invariance. Evidence was consistent with convergent validity. The estimated reliability of FBS scores was greater than .90 for both female and male pet owners. Conclusions: Results support use of the FBS in research on outcomes of pet assisted therapy, as well as the relationships between pet attachment and health and mental health of female and male pet owners.