This study investigated interactions between parents and 12-month-old infants at high (HR-SIBS; n = 27) and low (LR-SIBS; n = 14) familial risk for autism spectrum disorder (ASD). The contributions of parental variables, as well as child's autism symptom severity and verbal skills, to the parent interaction style were examined. Parents of HR-SIBS exhibited a higher level of synchronous-demanding behaviors, which was associated with parental report of atypical mood in the infant, but not with autism symptom severity, verbal skills, or parental depressive symptoms. These preliminary findings suggest a need for further investigation into HR-SIBS' emotional development and parental perception of that development, as these factors may shape parent-child interaction and influence the effectiveness of parent-assisted early intervention programs.