We report a 32-year-old male patient with early-onset Parkinson's disease who exhibited abnormally increased writing activity. The patient displayed a disabling and pronounced increased writing activity, filling up to 10 pages or more per day in a notebook, and spending more than 12 h writing. In general, there was not much meaning in most of the writing, though there was a particular preference in tabulating the names of various sport and TV personalities. The writing activity gradually diminished following treatment with quetiapine hydrochloride, an anti-psychotic agent, at 25 mg/day. Although the pathophysiological mechanism underlying the increased writing is unclear, we believe it should be regarded as a form of punding or stereotyped behavior that has been suggested to be associated with dopaminergic therapy in Parkinson's disease.