AbstractChildren exposed to parent conflict may be at risk for emotional and behavioral disorders by becoming sensitized to conflict cues in their environments. This study explored possible precursors to negative child outcomes associated with parent conflict by examining the relation between parent conflict and infants’ (N = 36; 23–42 weeks; 44% female) behavioral sensitivity to general sensory stimuli (e.g., loud noises, physical touch). To determine whether infants’ characteristic autonomic arousal and regulation moderated this association, infant baseline skin conductance (SC) and respiratory sinus arrhythmia (RSA) were measured. Parents reported levels of parent conflict, and mothers reported infants’ behavioral sensory sensitivity. The association between parent conflict and lower threshold for sensory sensitivity was strongest for infants with higher physiological arousal (higher SC) and lesser capacity for physiological regulation (lower RSA). Children may become more sensitive to environmental stimuli as a function of parent conflict during infancy, though this appears to depend on characteristic physiological arousal and regulation.