Background and objective: Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by degeneration of both upper and lower motor neurons. In this study, we aimed to measure both plasma and cerebrospinal fluid (CSF) phosphorylated neurofilament heavy chain (pNF-H) levels in patients with ALS, and determine if there is a correlation. We also evaluated plasma and CSF pNF-H levels to investigate if this biomarker could predict the time to generalization (TTG) in ALS better. Methods: Paired plasma and CSF pNF-H levels of patients with ALS (n = 51), multiple system atrophy (n = 12) and controls (n = 30) were measured by monoclonal sandwich ELISA. TUG, which also indicates the time of symptoms spreading from spinal or bulbar localization to both, was evaluated in all ALS patients. Results: We found a strong correlation between plasma and CSF pNF-H levels within individual patients (r = 0.712, p < 0.001). The mean TTG in ALS patients was 22.9 months (range 1-84 months), and there was an inverse correlation between plasma (r = -0.661; p < 0.001)/CSF (r = -0.869; p < 0.001) pNF-H levels and TUG. Conclusion: The correlation of plasma and CSF pNF-H levels would bring insight into the pathogenesis of ALS. TUG might play an important role in the future study of ALS, as an early indicator of survival. (C) 2016 Elsevier B.V. All rights reserved.