Himalayacetus lived in the ancient coastline of the ancient Tethys Ocean before the Indian Plate had collided with the Cimmerian coast. Like Gandakasia, Himalayacetus is only known from a single jaw fragment, making comparisons to other ambulocetids difficult.[4]
It was considered monophyletic by Uhen (2010). It was assigned to Pakicetidae by Bajpai and Gingerich (1998) and McLeod and Barnes (2008); and to Ambulocetidae by Thewissen et al. (2001) and Uhen (2010).[6]