Thirty adolescents with spina bifida and hydrocephalus were matched for age and I.Q. with thirty controls of different aetiology. A battery of eleven neuropsychological measures including the Wechsler Intelligence Scale, conceptual and planning skills, simple motor speed, simple tactile sensitivity, complex motor skill and complex tactile perception were administered to both groups. The index subjects differed from the controls in having a greater difference between verbal and performance I.Q., better complex motor skills, and slower left hand finger tapping speed. A step-wise multiple linear regression analysis correctly identified 80% of the subjects using the above three measures as the discriminating variables.