Early diagnosis in neurodegenerative diseases is important in terms of starting early treatment and increasing the quality of life of individuals. Therefore, effective diagnostic methods with low cost and fast results have an important place. In diagnosis, peripheral biomarkers are very few. Erythrocyte morphology as a potential biomarker is promising for future studies. Altered morphology may not only be used as a diagnostic biomarker but may also be important in the early pathogenesis of the disease. Here we reviewed importance of erythrocyte morphologies on the neurodegenerative pathologies- Alzheimer's disease (AD), Parkinson's disease (PD), Multiple Sclerosis (MS) Disease, and Epilepsy. Important studies on optical microscopy, scanning electron microscopy, atomic force microscopy, and quantitative phase imaging methods, which are widely used in the imaging of erythrocytes and detection of morphological changes in these neurodegenerative diseases, were reviewed from the literature.