Impaired social functioning is one of the diagnostic features of schizophrenia. Cognitive functioning is also often impaired in several domains. Meta-analysis has shown a predictive value of cognition for a variety of domains related to social functioning (Green, Kern, Braff, & Mintz, 2000). The significance of these findings for clinical practice has remained largely uninvestigated, however, and is therefore taken up here. We investigated verbal memory, attention and executive functioning in 52 schizophrenia patients. Social functioning was assessed for different types of social roles. The percentages of cognitive and social impairments in our group were assessed according to clinical principles, normally used to judge an individual patient. A possible predictive relationship between cognition and social functioning was studied on the basis of these clinical criteria. A large proportion of patients showed impairments in both cognitive functioning and social functioning. However, the clinical method resulted in a successful prediction of social functioning in only 21-69% of the cases. Social functioning and cognitive functioning were impaired in a large proportion of patients, but were largely independent from each other. Since relationships between cognition and social functioning are weak, assessment procedures are inconsistent and possibly not optimally adjusted to the psychiatric population, the clinical relevance of cognitive testing in order to predict social functioning is as yet questionable.