Located of the east coast of Fildes Peninsula, South of Ardley Island, at King George Island, Ostrov Geologov (Geologist Islands) is a small island with 0.25 miles long. It only had one plant record published so far. We have conducted extensive fieldwork on the site and provide here a comprehensive checklist and a key for the moss species occurring on the island. Despite its small size, theislandcontains about 35% of all theFildes Peninsula moss flora, six new records were found. The pristine state of the island due to its relative isolation, presence of avian nesting sites and a relatively rich moss flora are strong arguments in favor of protection status for the island.