The development of premature infants may be altered due to exposure to high cumulative doses of the perinatal corticosteroid dexamethasone during critical growth periods. To compare child behavioral development of prematurely born infants who were exposed to higher perinatal steroids (PNS; >0.2 mg/kg) with that of infants exposed to lower PNS (>0.2 mg/kg), we used the Vineland Adaptive Behavioral Scales to assess school-age behavioral outcomes of a historical cohort of 45 prematurely born infants. Children who had received higher PNS treatment were more likely to have lower overall behavioral developmental scores, especially lower social skills (p < .05). Higher PNS plus higher severity of illness during the first day of life based on the Clinical Risk Index for Babies (p = .016) and lower birth head size (p = .015) were linked with poorer behavioral outcomes among participants. Nursing practice includes promotion of quality care and should include closer evaluation of cumulative steroid therapy, severity of illness, and promotion of long-term follow-up support for premature infants.