A collection of fish scales from the La Meseta Formation (Paleogene, Eocene; Seymour Island, Antarctica) has been studied, permitting the characterisation of five clearly distinguishable morphotypes. Three morphotypes are comparable to scales of recent trachichthyids, clupeids, and gadids. The other two morphotypes are represented only by two poorly preserved specimens; however, they probably pertain to perciform and pleuronectiform fishes. The latter is a new record for the La Meseta Formation. The mixed composition of the fish scale assemblage reflects substantial redistribution of fish remains within a high-energy, shallow marine environment. Scales were recovered from calcareous sandstone concretions, which accounts for their overall good preservation. This is the most diversified assemblage of fish scales yet reported from the fossil record of Antarctica.