Previous studies have shown that schizophrenia patients display a left-lateralized reduction in cortical folding of the paracingulate cortex, although the functional significance of this anomaly is unclear. We examined the influence of paracingulate sulcus (PCS) asymmetries on cognitive performance in 37 male schizophrenia patients and 43 male controls. Across both groups, a leftward PCS asymmetry was associated with better spatial working memory performance than either a rightward asymmetric or symmetric folding pattern. This suggests that prior reports of impaired performance on such tasks in schizophrenia may be partly explained by the reduced frequency of a leftward PCS asymmetry in this population.