The racemic form of Selegiline was investigated in clinics a short time after its discovery in the sixties. However its fate seemed to be sealed by the so-called "cheese effect" associated with the applications of other MAO inhibitors. In the seventies the (-) enantiomer, called Selegiline was investigated again in European Clinics, and was finally introduced into therapy as an adjuvant of L-Dopa treatment for Parkinsonism. In the eighties its launch to the market of the USA was influenced by events known as the "MPTP Story" and the "Orphan Drug Act". Further clinical investigations of Selegiline are expected to clarify the real therapeutic value of Selegiline.