41 patients with arteriovenous malformations (AVM) of gyrus cinguli and 39 ones with AVM of hippocamp were examined. AVM verification was performed according to the data of angiography and computer tomography of the brain during the operation. 4 patients had generalized tonic-clonic seizures and absans. In these cases AVM spread from gyrus cinguli and hippocamp to the cortical medio-basal regions of frontal and temporal lobes of the brain. Autonomic paroxysms weren't found in the patients. Before the operation 73 patients had disorders of memory that progressed after the operation. Disorders of memory weren't completely identical in damages of gyrus cinguli or of hippocamp, namely: in damages of gyrus cinguli such disorders were similar in terms of their characteristics with those observed in damages of medio-basal regions of the frontal lobes, while in pathology of hippocamp--with those of diencephalic region (region of III ventricle). A conclusion was made about different participation of the structures studied in realization of the memory function.