The aim of the non-interventional Post Marketing Study is to investigate the use of the non-ergot dopamine agonist piribedil (trade name: CLARIUM) in mono- and combination therapy in patients with Morbus Parkinson. Tolerability and course of the disease or change of parkinsonian symptoms during stabilisation on, or change over from other dopamine agonists will be documented under routine conditions. Piribedil should be prescribed according to its marketing authorisation by the responsible neurologist.