Background: Biomarkers for Huntington's disease progression could accelerate therapeutic developments and improve patient care. Brain microRNAs relating to clinical features of Huntington's disease may represent a potential Huntington's disease biomarker in blood. Objective: This study was undertaken to examine candidate microRNAs in plasma to determine whether changes observed in HD brains are detectable in peripheral samples. Methods: Four microRNAs from 26 manifest Huntington's disease, four asymptomatic Huntington's disease gene carriers, and eight controls were quantified in plasma using reverse transcription quantitative polymerase chain reaction. Linear regression was used to assess microRNA levels across control, asymptomatic gene carriers, and manifest patients. Results: miR-10b-5p (P=0.0068) and miR-486-5p (P=0.044) were elevated in Huntington's disease plasma. miR-10b-5p was decreased in asymptomatic gene carriers as compared with patients with Huntington's disease (P=0.049), but no difference between asymptomatic gene carriers and healthy controls was observed (P=0.24). Conclusions: These findings suggest that microRNA changes observed in Huntington's disease brain may be detectable in plasma and have potential clinical utility.