Changes within the prefrontal cortex (PFC) have been associated with both mood disorders and with specific impairments in cognitive testing. The left PFC has been implicated in relational processing, that is, binding different pieces of information. We hypothesized that among older depressives and elderly controls, lower performance on one test of relational processing would be associated with smaller volume of the orbital frontal cortex (OFC). A total of 30 depressed and 40 control subjects were included in the study. All subjects were administered the Benton Visual Retention Test (BVRT). Subjects received a standardized magnetic resonance imaging, for which volumes of the OFC and total brain were calculated. We found that, controlling for age and education, total correct on BVRT was associated with left OFC volume normalized for total brain volume among the entire sample. For the depressed sample only, the number of perseverative errors was negatively associated with left OFC volume normalized for total brain volume after controlling for age and education. These results add to the literature linking mood and cognitive disturbances to the PFC. Future studies with a larger sample employing functional measures are warranted.