Neurodegenerative diseases are complex disorders that cause neuron loss, brain aging and ultimately lead to death. These diseases are difficult to treat because of the complex nature of the nervous system, and the available medicines are unable to heal them effectively. This fact implies the need for novel therapeutics to be designed that are ready to stop or a minimum of retard the neurodegeneration process. These days, Computer-Assisted Drug Design (CADD) approaches are a passage to extend the drug development efficiency and to reduce time and cost because traditional drug discovery is both time-consuming as well as costly. Computational or in silico methods came up with powerful tools in drug design against neurodegenerative diseases. This review presents the approaches and theoretical basis of CADD. Also, the successful applications of various in silico studies, including homology modeling, molecular docking, Quantitative Structure-Activity Relationship (QSAR), Molecular Dynamic (MD), De novo drug design, Pharmacophore-based drug design, Virtual Screening (VS), LIGPLOT Analysis, In silico ADMET and drug safety prediction, for treating neurodegenerative diseases have also been included in this review. Major emphasis is given to Alzheimer’s disease and Parkinson’s disease because these two are the most familiar neurodegenerative diseases.