Broken configuration errors on the WAIS-R Block Design subtest have been associated with right hemisphere brain damage. This study examined whether pre-surgical epilepsy patients with seizure foci restricted to the right hemisphere would break configuration more frequently than those with left hemisphere foci. Subjects included 38 patients with unilateral right or left hemisphere epilepsy of frontal or temporal lobe origin. The left and right hemisphere groups did not differ significantly in demographic or disease variables, IQ, or Block Design standard scores. Right hemisphere patients made more broken configurations than did those with left hemisphere foci. In the right hemisphere group, more broken configurations were associated with a lower Block Design Scaled Score and Full Scale IQ. These results suggest that the observation of broken configurations in the Block Design can assist in corroborating the seizure focus and highlight the importance of qualitative Block Design analysis.