Three cases of mirror writing ( MW) with left thalamic hemorrhage were reported. All were right handed and the MW was limited to the left hand. All showed slight deficit in short term memory and in calculation. But none showed constructional difficulty or unilateral spatial neglect. Only one of them was considered as aphasic.     MW was seen in voluntary writing and on dictation. Eye closure facilitated the tendency for MW. Also, it became more prominent when they had to write laterally from right to left than from left to right or in vertical direction. Automatic writing also facilitated the tendency while attention tended to suppress it. This tendency for MW seemed to fluctuate according to the level level of attention.     As for the mechanism of MW in three cases, we discussed a possible role of the left thalamus. MW in the left hand can be seen in normal person under certain conditions. Therefore the MW seen in these cases may simply be a disclosure of the normal latent tendency. Lesions in the left thalamus may have contributed to the appearance of the MW by disturbing the attentional mechanism.