During fish spoilage, microbial growth and metabolism generate different toxic metabolites among them biogenic amines. Biogenic amine formation has been prevented by optimizing handling and processing conditions, or by the addition of food additives up to their legal limits. However, the increased consumer demand to reduce synthetic additives in foods because of their potential toxicity and at the same time the increased interest for natural antimicrobials have led to increased effort to find such compounds. Several bioactive phytochemicals are used as food ingredients to improve the shelf life and sensory properties of food products. Thus, the application of plant extracts alone or in combination with food preservation technologies could be a good alternative approach to improve fish and seafood quality and safety without adverse effects on human health. The present review will summarize the information on natural antimicrobials from plant sources and discuss their different applications in fish and seafood products with an emphasis on their mechanisms of action to prevent bacterial growth and biogenic amines formation.