[8] The SCBI is a non-public facility devoted to training wildlife professionals in conservation biology and to propagating rare species through natural means and assisted reproduction.

[10] The zoo is home to birds, great apes, big cats, Asian elephants, insects, amphibians, reptiles, aquatic animals, small mammals and many more, but the best-known residents are giant pandas.

The SCBI facility houses between 30 and 40 endangered species at any given time depending on research needs and recommendations from the zoo and the conservation community.

[12][16] Together, they designed a new zoo to exhibit animals for the public and to serve as a refuge for wildlife, such as bison and beaver, which were rapidly vanishing from North America.

In the mid-1950s, the zoo hired its first full-time permanent veterinarian, reflecting a priority placed on professional health care for the animals.

In 2010, the complex was renamed the Smithsonian Conservation Biology Institute (SCBI), a title also used as an umbrella term for the scientific endeavors that take place on both campuses.

On 3,200 acres (13 km2) in the Virginia countryside, rare species, such as Mongolian wild horses, scimitar-horned oryx, maned wolves, cranes, and others live and breed in spacious surroundings.

SCBI's modern efforts emphasize reproductive physiology, analysis of habitat and species relationships, genetics, husbandry and the training of conservation scientists.

Rare and endangered species, such as golden lion tamarins, Sumatran tigers, and sarus cranes, breed and raise their young – showing the success of the zoo's conservation and research programs.

[8] The National Zoo has developed public-education programs to help students, teachers and families explore the intricacies of the animal world.

The zoo also designed specialized programs to train wildlife professionals from around the world and to form a network to provide crucial support for international conservation.

[17] Plans for the future include modernizing the zoo's aging facilities and expanding its education, research and conservation efforts in Washington, Virginia and in the wild.

As part of a 10-year renewal program, Asia Trail – a series of habitats for seven Asian species including sloth bears, red pandas, and clouded leopards – was created.

Near the island is Uncle Beazley, a fiberglass Triceratops that Louis Paul Jonas created for the DinoLand pavilion at the 1964 New York World's Fair.

The species on display include golden lion tamarins, golden-headed lion tamarins, emperor tamarins, Goeldi's marmosets, red ruffed lemurs, lesser hedgehog tenrecs, southern lesser galagos, black-footed ferrets, dwarf mongooses, long-tailed chinchillas, prehensile-tailed porcupines, two-toed sloths, red-rumped agoutis, brush-tailed bettongs, northern treeshrews, La Plata three-banded armadillos, screaming hairy armadillos, sand cats, fennec foxes, meerkats, naked mole-rats, rock hyraxes, striped skunks and several others.

Other animals kept and studied in the Think Tank include land hermit crabs, brown rats, and Allen's swamp monkeys.

[42] Other animals on display in the area prior to the renovations include a Hartmann's mountain zebra, addaxes, an ostrich, Grévy's zebras, maned wolves, Rüppell’s griffon vultures, sitatungas, scimitar-horned oryx, dama gazelles, red river hogs, Abyssinian ground hornbills and lesser kudu.

Animals on display include multiple species of freshwater stingrays, silver arowanas, yellow-spotted river turtles, red-footed tortoises, arapaimas, black pacus, a two-toed sloth, green aracaris, roseate spoonbills, hawk-headed parrots, guinea pigs and many more.

The habitats include: Delaware Bay, a marsh environment that displays shorebirds including red knots and semipalmated plovers, as well as cold-blooded species such as horseshoe crabs and native fish, Prairie Pothole, a wetlands environment that displays waterfowl including canvasbacks, redheads and American avocets, and Costa Rican Coffee Farm, a two-story tropical environment that displays migratory songbirds such as Baltimore orioles, indigo buntings and wood thrushes as well as barred parakeets.

Animals kept in the Kids' Farm include alpacas, hens, miniature Mediterranean donkeys, Hereford and Holstein cows, Kunekune pigs and Nigerian Dwarf goats.

The exhibit features two female bison, named Lucy and Gally, that were transported to the zoo in 2020 from the American Prairie in northeastern Montana.

[48] Other animals in the zoo's collection include spectacled bears (near the Amazonia exhibit), black-tailed prairie dogs (near the Claws and Paws Pathway exhibit), Przewalski's horses (near the Small Mammal House), Patagonian maras (near the American Trail), and Bennett's wallabies (also near the Small Mammal House).

[49] One of the most famous animals to have spent much of his life at the zoo was Smokey Bear, the "living symbol" of the cartoon icon created as part of a campaign to prevent forest fires.

[52] During President Richard Nixon's historic 1972 visit to China, the Chinese government donated two giant pandas, Ling-Ling (female) and Hsing-Hsing (male), to the official United States delegation.

On September 16, 2012, Mei Xiang gave birth to another cub, believed by zoo officials to have been a female, which died after about a week.

Initial results from a necropsy (animal autopsy) revealed the abnormal presence of fluid in the abdomen and also discoloration of the liver (hepatic) tissue of unknown etiology; the cub had managed to nurse before death because milk was found in its system.

Zoo officials said that, while upsetting, they (and, by extension, the public) can hope to learn more about giant panda breeding, reproduction, and health as a result, and will work closely and cooperatively with their Chinese colleagues during the inquiry.

[56] In January 2011, Dennis Kelly, director of the National Zoo, and Zang Chunlin, secretary general of the China Wildlife Conservation Association, signed a new Giant Panda Cooperative Research and Breeding Agreement, extending the zoo's giant panda program for five more years, further cementing the two countries' commitment to the conservation of the species.

A few days after announcing that they had detected fetal tissue, the zoo tweeted a short video of an ultrasound showing a panda fetus.

Its efforts support one of the four main goals of the Smithsonian's new strategic plan, which advances "understanding and sustaining a biodiverse planet.