Working memory and information processing speed were examined in children with myelomeningocele and shunted hydrocephalus using the Children's Paced Auditory Serial Addition Test (CHIPASAT). The CHIPASAT was administered to 31 children with myelomeningocele and shunted hydrocephalus and 27 healthy siblings, all between 8 and 15 years of age. They also completed other standardized measures of working memory and processing speed. Children with myelomeningocele made fewer correct responses than siblings, although the magnitude of group differences declined as the rate of stimulus presentation increased. Children with myelomeningocele also made fewer consecutive correct responses and were more likely to provide correct but nonconsecutive responses, suggesting that they responded in a way that circumvents the working memory demands of the task. Standardized measures of processing speed and working memory accounted for significant variance in CHIPASAT performance after controlling for age, group membership, math skill, and general intellectual functioning. The results indicate that children with myelomeningocele and shunted hydrocephalus display deficits in working memory and information processing speed, and suggest that the CHIPASAT may provide a valid measure of these skills. (JINS, 2006, 12, 305–313.)