This study examined the association between psychiatric symptoms and diabetes knowledge (DK) among 90 adults with serious mental illness (SMI) and type 2 diabetes. The relationship between DK and glucose control (i.e., AlC) was also examined. In a hierarchical linear regression, greater negative symptom severity and lower cognitive functioning both predicted lower DK, though cognitive functioning superseded negative symptom severity when analyzed simultaneously. A Pearson correlation showed no significant relationship between DK and Al C. Although symptom severity and cognitive functioning are both related to DI(among this population, cognitive functioning maybe particularly important. (C) 2016 Published by Elsevier Inc.