Life of sedentary organisms is inextricably linked with strong competition for space and resistance to the press of predators. The consequence of this in different groups of epibionts was the emergence of various adaptations that allow solving these problems. Formation of stable interactions with other inhabitants of benthic biocenoses has become a very popular strategy. Epibiotic, mutualistic and even parasitic relationships, allow not only to succeed in the struggle for a resource in the form of free space, but also provide other equally important advantages for survival. Bryozoans, being one of the most numerous groups of colonial invertebrates in marine benthic ecosystems, are not exception. This group of epibionts is characterized by both widespread and unique variants of symbiotic associations. This article provides an overview of all known forms of symbiosis of Bryozoa, fossil and modern, and discusses the implications of such relationships.