Parkinson's disease (PD) is a neurodegenerative disorder of the aging population with unknown etiopathogenesis. It is assumed that the underlying pathobiochemical processes comprise multifactorial and multigenetic disturbances leading to a progressive and devastating disorder without remission. Subtypes exist suggesting that "PD" is a spectrum disorder with variations in the cascade of pathobiochemical and genetic events. Neuroprotective endogenous processes are lost at the very beginning of PD. Supplementation of substances with neuroprotective and/or neurorescue capacity is eminent for future therapeutic strategies. MAO-B inhibitors, NMDA-receptor antagonists and dopamine receptor agonists fulfill such a criterion in preclinical studies while there is no clear evidence for clinical neuroprotection. However, PET-controlled studies comparing L-DOPA-treated and ropinirol-treated PD patients give evidence for the "concept of neuroprotective treatment strategies".