Microalgae are explored for his or her bioactive compounds with promising applications encompassing antibacterial, antiviral, antifungal and antialgal activities. Considering this status of widely used treatment therapies and their limitations to tackle their adverse effects, the appliance of bioactive compounds derived from algae will prove beneficial and far simpler as compared with traditional treatment methods. thanks to the emerging infectious diseases, viral infections (epidemic and pandemic) and lift in antibiotic resistant bacteria, there's an urgent need for development of other treatment therapies against infectious diseases. Present work provides a quick introduction about the algal bioactive compounds and their activities against various pathogens.