The relationship between frontal lobe phospholipid measures as measured by in vivo 31phosphorus magnetic resonance spectroscopic imaging and performance on the Wisconsin Card Sort Test was examined in 16 chronic schizophrenic patients and 13 normal controls. Lower left frontal phosphomonoester levels in the schizophrenics were associated with fewer categories achieved, lower percent conceptual level, and greater total errors. No significant correlations between frontal phospholipid measures and performance on the WCST were noted in the controls. The results suggest a relationship between altered left frontal phospholipid metabolism and a specific measure of frontal lobe neuropsychological functioning.