33 children with Specific Language Impairment (F 80, ICD 10) were randomly selected and their results regarding nonverbal intelligence, passive vocabulary and sentence comprehension were compared with data of 33 control children matched by age and sex. Although cognitive performance is average in both groups, significant differences regarding nonverbal intelligence are found. Whereas nonverbal intelligence is predictable from sentence comprehension to a high degree in den SLI-group, it is not predictable in the control group.