An association between negative symptoms and frontal cortex abnormalities has been suggested in schizophrenic patients. We tested whether this association can be found when patients' task performance is good and while controlling for possible cortical atrophy. We investigated regional cerebral blood flow with the xenon-133 inhalation method in 9 unmedicated schizophrenic patients at rest and during performance of the Continuous Performance Test. Negative symptoms were quantified with the Scale for Assessment of Negative Symptoms. All patients could attend to the test and performed it successfully with mean accuracy of 91 +/- 8%. Changes of the left hemisphere hyperfrontality ratio were significantly correlated with severity of negative symptoms, especially for the subscales of attention (r = -0.83) and anhedonia (r = -0.70). These results lend further support to the putative association between negative symptoms and physiological abnormalities of the frontal cortex in schizophrenic patients.