Since biological systems are often complex and comprising networks of multiple, interacting genes and their products, polypharmacology-baseddrug repurposinghas gained wider acceptance in recent years. We discuss the benefits and drawbacks of drug repurposing. We list the available computational resources, including databases and algorithms (particularly CLICK), for drug repurposing. We also detail virtual screenings, particularly genomic screenings andhigh-throughput screenings. Finally, we present the challenges associated with drug repurposing and our proposed solutions.