On 29 January 2010, the IUCN Red List of Threatened Species identified 6,702 (5,913 Animalia (1 Annelida, 1,328 Arthropoda, 3,814 Chordata, 149 Cnidaria, 617 Mollusca, 3 Nemertina, 1 Onychophora), 780 Plantae, 9 Protista) data deficient species.

Lists of data deficient species

• Animals
  • Amphibians — List of data deficient amphibians
  • Birds — List of data deficient birds
  • Fish — List of data deficient fishes
  • Invertebrates — List of data deficient invertebrates
    • Arthropods — List of data deficient arthropods
      • Insects — List of data deficient insects
    • Molluscs List of data deficient molluscs
  • Mammals — List of data deficient mammals
  • Reptiles — List of data deficient reptiles
• Plants — List data deficient plants
• Chromista/Protista — List of Chromista by conservation status (9 data deficient species)
• Fungi — List of fungi by conservation status (22 data deficient species)

Older lists (IUCN 2009.2)

• Annelida — IUCN Red List data deficient species (Annelida)
• Chordata — IUCN Red List data deficient species (Chordata)
• Cnidaria — IUCN Red List data deficient species (Cnidaria)
• Nemertina — IUCN Red List data deficient species (Nemertina)
• Onychophora — IUCN Red List data deficient species (Onychophora)
• Protista — IUCN Red List data deficient species (Protista)