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Background: Children with focal epilepsy unresponsive to anticonvulsant therapy may become surgical candidates. Inter-ictal SPECT (SPECT-IN) studies demonstrate an area of hypoperfusion within the seizure focus in up to 50% of patients. The goal of this study was to evaluate the usefulness of corregistration of MR and SPECT-IN images for localization of the epileptogenic focus. Material/Methods: Brain MRI and SPECT-IN were performed in 20 children (mean age 9.5). We found multifocal (3-6 perfusion deficits in 10 patients) or diffuse perfusion deficits (lobar) in all patients. In fused MR and SPECT images we evaluated average activity in volumes-of-interest (VOIs) outlined in each gray matter region with deficits. Average VOI activity below average total brain activity with at least 15% difference to the mirror VOI in the brain cortex on the opposite side of was considered as "true" perfusion deficit (TPD). Results: In all children from our group, MRI and SPECT-IN image fusion and evaluation of TPD allowed to verify most of multifocal or diffuse deficits: in each of 12 patients we found 1 TPD, in each of 6 patients 2 TPD and in each of 2 patients 3 TPD. In 8 patients with 2 or 3 TPD we used scalp EEG or ictal SPECT for identification of one probable location of epileptogenic focus. Conclusions: In children with refractory focal epilepsy, image fusion of MRI and SPECT-IN with evaluation of TPD has potential clinical utility in localization of epileptogenic focus.