Since 2009 in Pozos Colorados Bay, an artificial reef project for conservation, ecotourism promotion, and strengthen of communities has been functioning. In 2013 and 2015 six cubic and six pyramid modules were deployed respectively. In order to get to know part of the species richness associated to these structures, an assessment of the diversity of hydroids, corals, octocorals, and ascidians was performed through direct extraction and surface scrapes. The individuals were taxonomically identified to the species level and ecological annotations were taken during the surveys in order to understand the presence of the organism in the area, as well as to contrast this information with natural habitats. A total of 21 species were recorded, in descending order: hydroids (8), ascidians (7), corals (3), and octocorals (3). Five species are new records for the Colombian Caribbean (Leptogorgia hebes, Rhopalaea abdominalis, Didemnum cineraceum, Didemnum perlucidum, and Didemnum psammatodes) and the distribution range of other three species in artificial structures was expanded. Hydroids and ascidians dominated over corals and octocorals, due to their ecological features which allow them to use the habitat more effectively. In addition, the 2013 reefs had higher richness than the 2015, as it was expected by the increase in the structural complexity of the habitats with time. In short, the artificial reefs function as tools for biodiversity evaluation, with a great variety of the studied groups, which in addition improve the ecological niches for the benefit of other species in the trophic spectrum, in correspondence with the goals of its implementation in the area.