Missense mutations in LRRK2 (leucine-rich repeat kinase 2) contribute significantly to autosomal dominant PD (Parkinson's disease). Genome-wide association studies have suggested further that mutations in LRRK2 comprise a risk factor for sporadic PD. How LRRK2 contributes to PD, however, is largely unknown. Recent work has shown that LRRK2 is highly expressed in tissue and circulating immune cells and is suggestive of a potential role for LRRK2 in innate immunity. These studies and their potential implications for PD are discussed in the present paper.