At present, the discovery of drugs based on animal venoms undergoes its rebirth: pharmaceutical companies start to accept gradually the potential of animal venoms as combinatorial libraries of biologically active compounds. Sea anemones are a group of animals that produce the most structurally versatile polypeptide venom components, which distinguish them from the majority of other venomous animals. The known polypeptide toxins from the sea anemone venoms are considered in this review primarily in terms of their classification according to structural features. The most outstanding functional features of polypeptides within each class were analyzed.