Neurodegenerative diseases (e.g., Alzheimer's Disease, Parkinson's Disease and Amyotrophic Lateral Sclerosis), are characterized by the deposition of misfolded proteins (alpha beta-peptide, alpha-synucleine and Cu, Zn superoxide dismutase, respectively). Oxidative stress is accompanied by the diminished level of catecholamines in neuronal tissue. Beside their role in transduction of nervous stimuli, catecholamines might act as antioxidants. Herein, we focused on the antioxidant activity of catecholamine neurotransmitters--dopamine (and its precursor L-DOPA), adrenaline and noradrenaline. There is an increasing evidence that catecholamines might act as scavengers of free radicals and experimental data indicate the antioxidant potency of catecholamines. However, the exact mechanism of this action is not defined.