The findings of previous studies examining the neurocognitive development of children with clinically inapparent (asymptomatic) cytomegalovirus (CMV) infection have demonstrated mixed results. These studies have generally depended on small sample sizes (i.e., < 50). We examined the intellectual development of children with asymptomatic congenital CMV infection using a sample larger than previous studies. Two hundred and four cases aged 5 to 200 months were compared with 177 uninfected siblings ranging in age from 6 to 203 months. Parents were administered the Developmental Profile, a measure of developmental achievement. Children who were older than 30 months were administered an objective intelligence measure. Results of this study showed that children with asymptomatic congenital CMV infection do not demonstrate intellectual impairment, and that they perform similarly to uninfected siblings. Parents tended to overestimate their child's level of functioning regardless of whether the child had CMV infection.