The Zoological galleries of Government Museum, Chennai extend over eleven halls, adjoining the Sculpture galleries of the Archaeological section. In the ground floor galleries, exhibits pertaining to skeletons, dentitions, integumentary structures, reptiles, birds, mammals and some foreign animals are on display, while in the first floor galleries, invertebrates and fishes are on display.

Spectacular and outstanding exhibits in the Zoological galleries are as follows: the largest and most reputed among the exhibits in the Zoological galleries is the gigantic skeleton of the Great Indian Baleen Whale (Balaenoptera indica = Balaenoptera musculus) suspended from the centre of the ceiling in the hall of General Zoological galleries. This skeleton of whale, measuring over 60 feet in length was washed ashore in Mangalore in 1874 AD. The other notable skeletal exhibits in the museum are the huge skeleton of the Indian elephant and its skull with tusks, the skeleton of tiger, panther, kangaroo, dugong and the skeletons of man and horse.

During 1980, old sloping cases were replaced by modernised show cases in the General Zoology Gallery. All the exhibits were reorganised with miniature models of animals made of fibreglass materials so as to enable visitors to understand easily. Although the scope of the collections is limited to South Indian fauna, this museum has acquired a few birds and mammals from some foreign countries. Among the exhibits in these galleries, the orangutan, the tapir, the kangaroo, the duck billed platypus, the ostrich, the cassowary and the macaw parrots are the most outstanding ones. Apart from the few exhibits of foreign animals, the bulk of the museum collection consists of specimens of indigenous animals, which will give complete picture of South Indian fauna. Among the reptiles exhibited in the Reptile Gallery, a huge specimen of leathery turtle, a tortoise from Seychelles, specimens of the Indian species of crocodiles, a large number of South Indian species of poisonous and non-poisonous snakes and South Indian species of lizards are important exhibits. In the Bird Gallery adjacent to the Reptile Gallery, during 1960, the old show cases were replaced by modernised show cases with concealed lighting. In this gallery complete series of South Indian birds are arranged systematically in the natural sequence. The most unique and valuable of bird's collection are a pair of pink-headed ducks.

In 1988, the Children's Gallery, accommodated in the mezzanine floor of the new natural history block, was moved to the new Children's Museum building. Another group of bird collection (Passerine birds) displayed in the ground floor are shifted to the mezzanine floor of the new natural history block.

In recent years, new features introduced in the Zoological galleries are displaying animals, as pleasing and attractive as possible by exhibiting them in the form of illuminated dioramas. Eleven such dioramas were set up and open to the public in 1999 in the ground floor of the new natural history block.

The spacious hall on the first floor, directly above the old Mammal Gallery is devoted to the display of Indian fishes. In this gallery, an enormous specimen of the whale shark is displayed suspending from the ceiling. This specimen is twenty-two feet long and was captured in Chennai in 1889 AD. The other fishes of the Indian waters, such as Rayner’s shark, the saw fish, tiger shark and the sword fish impress the visitors by their unusual size and structural peculiarities.

Besides the outstanding exhibits of Vertebrate animals, the Zoological galleries possess a wealth of materials comprising the lowly organised Invertebrate animals. The collection of corals exhibited in the front hall of the Invertebrate Gallery includes a wide range of specimens of various species. The notable exhibits in the Invertebrate gallery are sacred chank and other molluscan shells, starfishes, sea urchins and insects.

Besides the exhibited specimens, the Zoological section possesses a large reserve collection consisting of over a thousand specimens stored in jars and several hundreds of dry preserved specimens preserved in boxes and cabinets.

Dr.Edward Green Balfour, the first officer-in-charge and organiser of Government Museum, Chennai, in 1851 AD had very clear ideas of the functions of the museum, “to contain complete collection of the natural production of the country and other parts of the world, duly named and systematically arranged as a means of encouraging the study of Natural History and to do its share in the advancement of science”. Dr.Balfour started collection campaign and acquired valuable collection of fishes, as it reflects in the first letter, letter book of the Museum dated 9th June 1851 AD thanking Dr. A.Lorimer, M.D. Secretary to the Medical Board “for the very valuable present of fishes” to the Government Museum on 17th May 1851 AD.

Captain Jesse Mitchell who succeeded Dr.Balfour on 15th May, 1859 AD acquired shells, fishes, birds, insects and fossils from several Museums from foreign countries in exchange for similar materials sent from Madras.Major Michael secured in 1865 AD for the Museum the femur, tibia and tarsus of Moa, a rare huge bird from New Zealand. Another important exhibit in the Zoology Gallery, acquired during captain Mitchell’s tenure of office (1859 – 1872 AD) was the skeleton of horse of which was his regimental charger. This skeleton is exhibited in the General Zoology Gallery.

When Surgeon – Major M.C. Furnell, F.R.C.S., officiated as the Superintendent of the Museum for about eighteen months from June 1874 AD, during Dr. Bidie’s absence on sick leave, the important event was the acquisition of the skeleton of a whale for the Museum. “This enormous sea mammal was cast on shore near Mangalore and was secured by Mr. Thomas, the Collector. The bones were brought to Madras by a vessel of the British India Steam Navigation Company free of charge. The bones were macerated and the complete skeleton was mounted and exhibited. The Museum was very proud of acquiring such a huge skeleton.

The Head Taxidermist of the Museum, Mr. Anthony Pillay, won a silver medal at the Fine Arts Exhibition held in England for a group of birds and reptiles, prepared by him in 1867 AD. In 1877 AD he won another silver medal for “preserved fish specimens” from the Maritime and Piscatorial Exhibition held at the Royal Aquarium, London.