Wernekink commissure syndrome is a rare midbrain syndrome, which selectively destroys the Wernekink commissure involving the decussation of superior cerebellar peduncle in midbrain. This syndrome may display a clinical picture: bilateral cerebellar ataxia, eye movement disorders, and palatal tremor. We present two cases of the Wernekink commissure syndrome with acute onset of bilateral cerebellar dysfunction confirmed by magnetic resonance imaging. One patient presented internuclear ophthalmoplegia, but neither showed palatal tremor. It is notable that the bilateral cerebellar dysfunction may be ascribed to midbrain lesion involving the Wernekink commissure, and it may be the sole manifestation of the midbrain lesion.