The Eurasian otter has one of the widest distributions of all Palaearctic mammals (Corbet, 1966). Its range covers parts of three continents: Europe, Asia and Africa. Its current distribution in Europe is marked by a large corridor, reaching from Central Denmark, via the Western parts of Germany, the Netherlands, Belgium, Luxembourg, the Eastern parts of France, Switzerland, the Western pmts of Austria to Central Italy, where the otter is extinct or reduced to small and sometimes isolated populations. Information for Russia, which forms a link between Europe and Asia, is fragmented. It seems that the otter is distributed throughout the country with the exception of the tundra and the northern regions with permanent frost. The southern border of the Eurasian otter's range in the Near and Middle East is formed by Israel, Jordan, Iraq and Iran. It is also reported from Morocco, Algeria and Tunisia in Africa in the north of Sahara. In south Asia the species has been reported from all most all the countries especially from Himalayan River systems of Pakistan, Afghanistan, India, Nepal, Bhutan and Myanmar and eastward throughout South East Asia up to Japan where it believed to be extinct.

There are several open questions for the Southeast Asian region. It seems that the Eurasian otter reached the island of Sumatra but, did not reach the island of Java. Conroy et al. (1998) are not sure if the evidence of otters on the island of Borneo really relates to the Eurasian otter. Its occurrence has been confirmed from South Korea, Southern China, Viet Nam, Cambodia, Lao PDR, Myanmar and Bangladesh (Lekagul and McNeely, 1988, Hussain 1999). In India it occurs in Northern, North East and from Southern India. Formerly widely distributed in Japan, it is now believed to be extinct (Ando et al. 2007). Once widespread in the rivers of northern Mongolia (Mallon 1985), along the rivers of Mongol Altai Mountain Range, and along the Halh River in Ikh Hyangan Mountain Range (Bannikov 1954; Dulamtseren 1970; Sokolov and Orlov 1980). It has also been reported from downstream of the Tengis River in northern parts of Hövsgöl Mountain Range (Tsagaan 1975; 1977) and around the Eröö River Basin in western Hentii Mountain Range (Tsendjav 2005). The Eurasian otter can also be found occasionally along the Tes River in northern Hangai.