The conservation of aquatic mammals, as well as mammals related to aquatic ecosystems of the con- tinental and oceanic Colombian Pacific Coast, represents a number environmental, socio-economic, and political challenges. This article identifies the major conflicts that threaten the diversity of this group of mammals, such as incidental mortality, the use of some of the species as bait in commercial and traditional fishing practices; destruction and pollution of their habitats; limitations in environmental education and conservation plans; short-term investigations; lack of funding for conservation strategies; as well as the lack of comprehensive conservation policies. Forty three aquatic mammals and mammals associated to aquatic ecosystems have been documented for the Colombian Pacific. These species, belong to 29 genera, 15 families, and 6 orders, representing 8.7% of the Colombian mammalian fauna. Four of these species are endemic of the South American Pacific. Among these diversity, 11.6% of species are classified as Critically Endangered (CR), 4.6% as Endangered (EN) and vulnerable (VU), 27.9% was caterized under the category of Deficients Data (DD), and 51.2% as Least Concern (LC).