The museum houses the largest zoological collection in Lithuania, with about 300,000 specimens of various zoological preparations: stuffed animals, skeletons, skulls, study skins, fluid-preserved specimens, eggs, mummified (dry) specimens etc. From tiny-scale insects to giraffes. One part of the collection is for teaching objectives (exhibition, demonstration), and the other is for purposes of scientific research. The collections are divided into groups: mammal collections (8,000) specimens; avian collections (12,000); herpetology collections (3,700); fish collections (3,400); invertebrate collections (56,000); entomology collections (202,000). The most valuable collections: are the beetle collection of K. Arris “Coleoptera Palearctica”, the conchology collection of V. Matuzevičius, and the collection of animal type specimens.