We investigated an organic solvent abuser who developed amotivational syndrome employing neuropsychological examination (Rorschach test, Bender Gestalt test and Benton visual retention test), electroencephalography, magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The patient manifested a disability to maintain a goal-orient mental activity, immature reality testing and poor set shifting, which suggest frontal lobe dysfunction, as we have reported before in neuropsychological examination. In this case, single photon emission computed tomography (SPECT) also revealed a decrease of regional cerebral blood flow (rCBF) in the medial frontal lobe. These results may suggest a contribution of frontal lobe (especially medial frontal lobe) dysfunction to the pathogenesis of amotivational syndrome due to organic solvent abuse.