In 2021, the Rarities Committee of the Slovak Ornithological Society/BirdLife Slovakia reviewed 56 records, of which 46 were accepted in the category A, one in category C, two in category D and two in category E. Furthermore, four breeding records were accepted. Two records of Brant Goose (Branta bernicla), one record of Pink-footed Goose (Anser brachyrhynchus), three records of Lesser White-fronted Goose (Anser erythropus), three records od Tundra Swan (Cygnus columbianus), one record of Baillon´s Crake (Zapornia pusilla), one record of Sociable Lapwing (Vanellus gregarius), two records of Collared Pratincole (Glareola pratincola), one record of Black-winged Pratincole (Glareola nordmanni), two records of Pallas´s Gull (Ichthyaetus ichthyaetus), one record of Great White Pelican (Pelecanus onocrotalus), one record of Black-winged Kite (Elanus caeruleus), three records of Greater Spotted Eagle (Clanga clanga), one record of Booted Eagle (Hieraaetus pennatus), nine records of Pallid Harrier (Circus macrourus), one record of Yellow-browed Warbler (Phylloscopus inornatus), one record of Common Chiffchaff (Phylloscopus collybita tristis) and one record of Rosy Starling (Pastor roseus) were the most interesting records in 2021. Alpine Swift (Tachymarptis melba) nested in Slovakia for the first time and the rare breeding of Canada Goose (Branta canadensis) (presumably a free-living pair originally escaped from captivity) was documented. Rarities Committee accepted observations from the year 2021, but also some valuable observations from years 2018, 2019 and 2020. For example, one record of Pallas´s Gull, one record of Parasitic Jaeger (Stercorarius parasiticus) and one record of Yellow-browed Warbler.