Generally, antimicrobial peptides (AMPs) are considered as an important part of innate immunity, due to which they provide the first line of defence against various pathogens. Additionally, they also kill pathogens that show resistance towards many antibiotics. Fishes are regularly challenged by various pathogens which not only affect their health but the risk of becoming resistant to conventional antibiotics is also increasing. As fishes shows more dependence on innate immunity, AMPs can aid as important defensive weapon in fishes. In general, AMPs exhibit various multidimensional characteristics such as neutralization of pathogens (viral, fungal & bacterial), rapidly diffuse to the infection site, and other immune cells recruitment to the infected tissues. AMPs also show various biological effects such as immunomodulation, neutralization of endotoxin and angiogenesis induction. There are numerous AMPs that have been isolated from fishes but not fully characterized at molecular level. In this review we basically focus on approaches used to design new AMP, machine learning approach, current objectives of AMPs and future prospects.