Parkinson's disease (PD) is a common neurodegenerative disorder that is most often sporadic, but in some cases it can be inherited as a simple Mendelian trait. The most important pathological feature of the disease is the death of brainstem dopaminergic neurons in the substantia nigra, which leads to characteristic motor symptoms. The etiology of PD remains unknown, but mitochondrial dysfunction and oxidative stress may contribute actively to the underlying pathomechanism. New studies suggest that K(ATP) channel activation may represent a downstream effector of these two cellular anomalies.