Polyglutamine (polyQ) disease is a group of hereditary neurodegenerative diseases. It has become clear that brain damage may occur decades before the onset of symptoms. As a sensitive marker for neuro-axonal damages, neurofilament light chain (NfL) has appeared as a promising biomarker for neurological diseases. it may be used as a preclinical and clinical marker for the neurodegeneration in polyQ diseases, and is closely correlated with disease severity and progression, in particular different disease stages. This article has provided a review for the value of NfL as a biomarker in polyQ disease and its future research directions.