Parkinson's disease is a progressive and debilitating disorder that has so far eluded attempts to develop disease-modifying treatment. Both epidemiological and genetic studies support a role of neuroinflammation in the pathophysiology of Parkinson's disease. Postmortem studies and experimental analyses suggest the involvement of both innate and adaptive immunity in the degenerative process. There is also some circumstantial evidence for effects of immune therapies on the disease. In the present article, we review 10 unanswered questions related to neuroinflammatory processes in Parkinson's disease with the goal of stimulating research in the field and accelerating the clinical development of neuroprotective therapies based on anti-inflammatory strategies. © 2020 International Parkinson and Movement Disorder Society.