The association of unusual types of aphasia and epilepsy (Landau-Kleffner syndrome) has been described in three children. The children were 5 to 11 years of age and all have EEG abnormalities. Speech disorders appeared after epileptic seizures. No organic causes of the disease have been found in axial computed tomography. In all described cases the increased titer of IgG antibodies against Toxoplasma gondii has been observed. The authors suggest that the Toxoplasma gondii infection should be taken into account as a possible cause of Landau-Kleffner syndrome.