In spite of great advances in modern medicine, there are a few effective strategies for the treatment of neurodegenerative diseases characterised by neuron loss or degeneration. This results from complex pathogenesis of the diseases and the limited drug uptake of the brain due to the presence of blood-brain barrier. Nanoparticle-based drug delivery systems are expected to improve the drug utilisation. Polymeric nanoparticles represent promising drug delivery carriers to the brain due to their unique advantages such as good biodegradability and biocompatibility, flexibility in surface modification and nontoxicity. In addition, the delivery of genetic drugs may stop the progression of neurodegenerative diseases at the genetic level and even avoid the irreversible damage in the central nervous system. In this review, an overview of studies on polymer-based nanoparticles for drug delivery to the central nervous system in typical neurodegenerative diseases, especially Alzheimer's diseases and Parkinson's diseases, is described. Meanwhile, their applications in gene delivery in these disorders are discussed. And the challenges and future perspectives for the development of polymeric nanoparticles as drug delivery carriers in neurodegenerative diseases are concluded.