Levetiracetam (LEV) is a novel anticonvulsant that is currently investigated in bipolar disorder. It may be useful in the treatment of refractory and complicated cases, in which conventional mood stabilizers are not effective. We report two cases of rapid cycling bipolar disorder in which the add-on of LEV to a conventional treatment regimen improved symptoms of depression, as well as those of mania/mixed mania, and disrupted the severe rapid cycling pattern.