The authors report the results of a floristic study of the benthic macroalgae from Terra Nova Bay (Ross Sea, Antarctica) based on collections made during two Italian expeditions to Antarctica. A brief description, phytogeographic data and, where necessary, taxonomic and nomenclatural observations are given for the 17 taxa encountered (9 Rhodophyceae, 4 Fucophyceae and 4 Chlorophyceae).