Bryozoans are major components in fouling communities, showing characteristics that facilitate their introduction into new areas mainly through hull fouling. Artificial structures in marinas are key for the introduction of bryozoan non-indigenous species (NIS), acting as a reservoir for their further spread to other areas. Considering that NIS management should be preventative, a comprehensive understanding of bryozoan diversity in marinas is mandatory. This is especially relevant in areas that rely heavily on shipping, such as the Canary Islands, where this information is still lacking. Here, we assessed bryozoan diversity in recreational marinas of Tenerife, Gran Canaria, Fuerteventura and Lanzarote. We found 24 taxa: 12 NIS, eight cryptogenic species and four unassigned. Seven of these species constituted new records for Canary Islands, including three for Spain, four for Macaronesia and two for the North-Eastern Atlantic. Primary taxonomical, faunistic and ecological studies are crucial to properly conduct adequate management programmes for NIS.