Résumé : Two patients suffering from a left thalamus infarct were studied over a long period. The precise location of the lesion has been demonstrated by the C.T. scan. In spite of the absence of any cortical lesion, both presented with aphasia and other neuropsychological disorders (left-right confusion, dyscalculia and possible finger agnosia). Their speech disorders although different, had several features in common. The observations were compared with the other cases reported in the literature.