Background and Purpose. Federal law mandates family-centered care as the service delivery model in early intervention programs for children from birth to 36 months of age. This study investigated the relationship of therapists' attitudes, children's motor ability, and parenting stress to mothers' perceptions of physical therapists' family-centered behaviors during early intervention. Subjects and Methods. Twenty-five physical therapists and 75 mother-child dyads (3 from each therapist's caseload) participated. The mean chronological age for the children was 21.2 months (SD=7.3, range=6–35). Mothers participated in a structured interview using the Measures of Processes of Care (MPOC-56), and they completed the Parenting Stress Index-Short Form (PSI-SF) and a questionnaire. The Bayley-II Motor Scale was administered to the children. Therapists completed a modified version of the Measures of Processes of Care for Service Providers (MPOC-SP) and a questionnaire. Results. Scores for mothers on the MPOC-56 and for therapists on the MPOC-SP indicated strong positive perceptions and attitudes toward family-centered behaviors. Hierarchical multiple regression analyses indicated that parenting stress explained a considerable amount of the variance in mothers' perceptions of family-centered behaviors, whereas therapists' attitudes explained a considerable amount of the variance in mothers' perceptions of respectful and supportive care. Children's motor ability was inversely related to parenting stress. Discussion and Conclusion. Findings suggest that mothers perceive that physical therapists are using family-centered behaviors in early intervention. Findings from the questionnaires suggest that some early intervention policies may be barriers for therapists and prevent them from actualizing attitudes toward family-centered behaviors.