In Parkinson’s disease (PD), the traditional focus has been on bradykinesia, rigor and tremor, but non-motor symptoms such as gastrointestinal and sleeping disturbances, depression or cognitive deficits have gained increasing attention in recent times. Many of these non-motor symptoms respond but insufficiently to the classical, mainly dopaminergic, medication and thus substantially limit the quality of life of afflicted patients. This justifies searching for novel, effective and non-dopaminergic therapeutics. The adenosine A2A receptor antagonists were developed as just such a therapeutic option because adenosine A2A receptors are non-dopaminergic and are localized selectively in the basal ganglia. This introduces the additional possibility of modulating striato-thalamo-cortical loops. In 2013 an adenosine A2A receptor antagonist was already approved in Japan as an add-on to levodopa, and then in 2019 in the USA. In this review we hope to outline (1) the theoretical and mechanistic basics of this therapeutic approach as well as (2) the current data on its effectivity for both motor and non-motor symptoms and in addition (3) its potential neuroprotective effect.