Diagonistic dyspraxia is a clinical syndrome usually characterized by involuntary and conflicting behaviors between the hands following corpus callosum lesions. In the present study, we report the case of a patient who presents such symptoms, along with a series of complex abnormal behaviors, such as carrying out an action and subsequently doing the exact opposite, or being unable to choose between two alternative decisions. The data reported in this study indicate that, at least in some patients, diagonistic dyspraxia can be associated with abnormal, antagonistic, behaviors not limited to the hands. In our view, diagonistic dyspraxia result from lesion of the posterior corpus callosum while associated complex abnormal behaviors result from concomitant anterior lesions.