Background/Methods: Sensory processing capacities of 8-12-year-old internationally adopted (IA) children who experienced prolonged institutional care (greater than 12 months with 75% of pre-adoption lives in institutional care) prior to adoption into family environments (PI) were compared to a group of IA children who were adopted early (less than 8 months) predominantly from foster care with little or no institutional experience (EA/FC) and another group of non-adopted (NA) children raised by their birth parents in the United States. All children had estimated IQs within the normal range and did not evidence major neurodevelopmental disorders (e.g., cerebral palsy, fetal alcohol syndrome, Down's syndrome). Sensory processing was evaluated with a commonly used parent-report measure and a laboratory assessment. Results: Children who had experienced prolonged institutionalization showed higher levels of reactivity to sensation and displayed both more aversion and approach to sensory stimuli than the other groups. The comparison groups (EA/FC & NA) did not differ on any of the sensory processing measures. Conclusions: These results suggest that early institutional rearing which typically involves both sensory and social deprivation is associated with problems in sensory modulation capacities.