The Arabian Peninsula contains a wide diversity of sand and gravel deserts, mountains, coastal and offshore habitats and sparse wetlands. It also contains a diverse mammal fauna which comprises a mix of Arabian endemics, species with affinities to the Horn of Africa and Saharo-Sindian, Iranian-Central Asian, and Mediterranean elements. There are 166 terrestrial and 23 marine species whose occurrence in the region is confirmed, giving an overall total of 189 confirmed species. The status of the terrestrial species was assessed using the IUCN Red List Categories and Criteria and application of the IUCN Regional Guidelines. The distribution and status of each marine mammal species was reviewed and updated.