Due to the lack of effective vaccines and efficient chemotherapy against parasitic infections, the development of antiparasitic innovative medications is an urgent issue. Marine invertebrates were considered as a major source of useful pharmaceuticals. Despite the fact that there has been relatively little research on the bioactive chemicals of the sea-dwelling phylum "Bryozoa", bryozoans have proven to be a rich source of novel therapeutic compounds. In the present article, studies on the antiparasitic effects of chemicals isolated from bryozoans that have been published over the last two decades were reviewed. A total of 26 bryozoans' compounds were investigated as potential antiparasitic compounds from four different genera of Bryozoa. In vitro activities of these compounds against five parasites, Trypanosoma  brucei brucei, Plasmodium falciparum, Leishmania braziliensis, Trichinella spiralis, and Haemonchus contortus were reviewed. The challenges of developing these chemicals into functional treatments, as well as the reasons for the lack of research on bryozoans' animals, were discussed in the present systematic review.