This study was aimed at exploring the prokaryotic communities associated with the sponge species Mycale acerata (Kirkpatrick, 1907) and Dendrilla Antarctica (Topsent, 1905) collected from two distant Antarctic locations, i.e. South Cove at Rothera Point (Adelaide Island, Antarctic Peninsula) and Thetys Bay (Terra Nova Bay, Ross Sea), and at comparing them to deepen our yet scant knowledge on the prokaryotes-host specificity in such extreme environment.